I personally like the styling of the G-cars, as the Georgetto Giugiaro styled cars are called, and the S1s in particular, as the purest form of the Esprit. That's why I bought one. As mentioned earlier, they are also the most prone to problems of all of the Esprits.
Lotus has always had a somewhat tenuous existance from a financial standpoint. This was especially true in the 70's and 80's. The Esprit was rushed to market, from a developmental standpoint. Each year, over the entire 28 year model run there were continuous improvements in engineering and manufacturing. All of this lead to continuous improvement in vehicle dynamics, reliability and quality.
There are some specific issues (in no particular order) that need to be kept in mind when considering purchase of one of the early cars (S1's and S2's):
Rear axles: These cars had U-joint rear axles that formed the upper rear suspension link. As a result the side loads due to cornering are transmitted directly to the transaxle bearings. Check for leakage and slop at these bearings. Also check the U-joints. A failure here during driving could be ugly.
Motor mounts: The very early cars had a poorly designed motor and gearbox mount system. The mounts did not resist fore - aft forces. As a result accelleration forces would allow the engine / transaxle assembly to shift forward in the chassis. There are a couple of fixes for this problem that include a thrust rod that limits the movement and a new set of front motor mount brackets that utilize the S3 / Turbo style rubber mount / vibration isolator (I have these on my S1 and they are excellent).
Motor mount heat shield:
The exhaust side motor mount is prone to deterioration due to the heat radiating from the nearby exhaust manifold. It is a good idea to fabricate a heat shield to increase the life of this rubber mount. It is not as severe on the non turbo cars, but it is still an issue.
Shift linkage: The shifter arm on the transaxle on the S1 and S2 is on the left hand side of the car. This is the same side as the exhaust of the engine. The rubber vibration isolator bushings in the linkage in this region deteriorate quickly due to heat, oil and dirt contamination. This is a source of continuous maintenance unless remedies are made. Your choices include various "hard" bushings that range from nylon / delrin / urethane bushings (you fabricate them yourself) to installation of sperical bearings (Heim joints). These approaches provide improved shift "feel" at the expense of increased vibration transmission into the cockpit. You could also swap the linkage from a Turbo. This would be a fair amount of work and require the acquisition of the Turbo shift linkage, chassis bell crank assy and gearbox top cover. I have taken the continuous maintenance approach here.
Headlight drive motor:
The early cars had a single motor to raise and lower the hadlights. If not in good condition it is not up to the job. Some of the S1s and most of the S2s had a 2 motor system. It is a big improvement in reliability. My car is a very early S1 with the single headlight motor. Again, I have taken the continuous maintenance approach.
The heaters in the early cars are OK. The A/C not so much. I guess that it just doesn't get that hot in the UK.
Many owners report cooling problems with the early cars. I haven't had any problems. The radiators are quite small and the 3 fans are required to get adequate air flow. If one of them fails or if the radiator gets clogged with road debris, restricting airflow, you will have problems. Many owners have upgraded the radiator. Also the fan blades leave a lot to be disired from an aerodynamic point of view. There are significant gains to be made here if you want to spend the time and money to install modern aftermarket fans or a larger radiator. However, just installing a thicker radiator is not necessarily a panacea. It is important to keep the airflow pressure drop to a minimum to get good heat transfer performance out of a radiator. If the airflow is restricted, by debirs, corrosion or due to the flow characteristics of the radiator itself, cooling performance will suffer. I have the OEM radiator / fans and don't have any problems here in SoCal in the summer. I guess that I've just been lucky in this respect.
Each of the fuel tanks has a 3-point mounting system. There are 2 bolts, one in the engine bay, one in the rear wheel well and a foam rubber pad under the tank. The fuel tanks are made from mild steel and painted black. They were not prepared well before painting at the factory (or by the vendor who supplied them). The result is that if water gets into the foam pad under the tank, the tank rust out. This is a very common problem. It is one of the sources of "trial by fire" for Esprit owners. My car has lived it's whole life in SoCal. Lucky for me the tanks are pristine. I also replaced the factory foam with 1/2" thick closed cell foam (neoprene, like wet suit material) while the engine was out.
The fuel vent lines that go over the rear window are prone to deterioration over time. These need to be checked carefully and replaced if necessary with high quality material. Failure of these lines is likely the most common "trial by fire" problerm for Esprit owners.
Electrical connections, switches and window motors:
All I can say about this is that the cars were built in the UK in the 70's and used mostly Lucas components. The power windows are driven directly by the switches instead of via relays. The switches fail due to the hig current loads at their contacts. You will want to consider powering the3 window motors via relays to solve this. The ubiqutous use of barrell wire and switch connectors that do not have good corrosion resistant sealing provisions leads to electrical system failures over time. The electrics work fine until high resistance connections become problematic over time. Again, the dry SoCal weather has been good to my car in this respect. The switch gear is difficult to come by. I searched for a headlight switch for my car for a year (actually, this has been the only really difficult part for me to source for my car).
OK, so the list above covers most of the fixes I have made to my car. I could go on, but you get the idea. My car has proven to be completely reliable since going back together. It had 29k miles when I bought it --- with a blown engine and gearbox. So I rebuilt both of those too, making performance improvements in those areas as well.
As for performance it is faster than a Miata. But not a lot. I know. We have a '94 Miata in our stable. My car makes about 175 Hp. It will go about 125 flat out. I'm guessing it is somewhere around 7 - 8 seconds 0-60. It is reasonably quick 40 - 90 mph. Much quicker in this respect than the Miata. The lack of the wrap around front air dam makes it much more suseptable to cross winds than the Turbo cars ('82 and later).
Even by today's standards the cars ride and drive very well. The low speed steering is heavy, in say a parking lot. But beyond 5 mph it is perfectly weighted. The relationship of the steering wheel to the shift lever is perfect. If you are 6' tall or under the driving position is also excellent. However if you are taller or have a waist larger than about 36" you may find the interior room to be problematic. If you are over 6' there are fixes to the seats and pedals that can make a significant difference. I'm 6'5" and fit just fine after some work on the seats and pedals.
By following the prescribed maintenance practices / schedules, particularly valve / cam belt adjustments, and chassis lubrication, I have found that the car is reliable. But you can't ignore maintenance or it will bite you.
There is one more thing to remember about living with the car day to day: In general many women don't like to wear skirts when getting in and out of the car. It is not the easiest car to get into and out of. It requires a wide parking space and the doors don't swing open very far. It is very low and the side sills are quite wide. As a result you have to sort of climb out. Problematic when wearing a dress!
Go out and purchase some Esprit books and study up before you go out to buy. I recommend the following as a good start:
Lotus Since the 70's, Vol 1 & 2, by Graham Robson.
Lotus Esprit, by Jeremy Walton.
Lotus Esprit, by Gerard Crombac.
Lotus Esprit, The Story So Far, by William Taylor.
I also recommend that you get involved with one of the Lotus clubs, if there is one in your area, or Lotus Ltd, if not. Go to some events. Try to get a ride in a couple of cars from members if possible so that you'll know what to expect. Especially if you're going to buy a non-running car.
'84 Turbo (x2)