I am first considering the V8 and second the S3 Turbo.
Not to put too fine of an edge on this thread, but there was a Type 85 Esprit S3 with a naturally aspirated 912 engine. Then there was the Type 82 Turbo Esprit with the 910 engine. But there was no "S3 Turbo". I know... picking nits.
Have you ever driven an early Lotus? Seven/ Elite/ Elan... a Europa would be the most Esprit-like, since both are mid-engined. All the early Lotus models were very light weight (my Europa is about 1400 lbs), and there was a 'Delicate Lightness of Being' associated with driving them. Then government mandated standards stepped in, and 1974-onward Lotus cars became far heavier... and kept getting heavier, until the Elise.
If you have ever driven an early Lotus, then you can appreciate the importance of lightness, and the impact of weight.
The Esprit is one of the 3rd Generation cars, one of the heavy generation. And it continued to gain weight with each new model. On the other hand, it also picked up more creature comforts, build quality, A/C, bells & whistles, and POWER.
One philosophy is to buy an early Turbo to get a lighter weight car with lighter controls with crisp handling & feedback; another philosophy is to buy the newest car you can afford since it will be more developed and have fewer problems, offer more comfort & luxury, and then just rely on the greater power for performance.
That's not meant to take anything away from the later Esprits. By any standards, they are marvelous cars that are arguably better handling than the competition of their day. But finesse your way into a back-to-back drive in an early G-Turbo, and a late V8. Not on the freeway... find some nice twisty roads. Both cars will impress, but in different ways. Then choose the one 'you' prefer. Asking for opinions is like asking others to tell you which woman you should marry. Some decisions you need to make on your own.
The V8's power is impressive, and it's easy to use... it launches when you mash down on the throttle pedal. By comparison, the early G-Turbo doesn't have the over-whelming power, but it's steering is light, nimble, with crisp feedback. In the twisty bits, tell it to go there, and it's there before you finish the thought. It's quick from point A to B, but you need to 'work' for it... while in the V8 you just step on the pedal and jump to light speed.
If you like the twistie bits, then you cannot ignore the effects of mass in a corner. If you don't have to slow down going into a corner, then it doesn't matter how quickly you accelerate coming out of the corner.
560 kg (1235 lbs), 185 bhp, 299.6 Bhp/Ton -- Europa Type 47 <<<<<<<<< Highest Bhp/Ton on this list.
612 kg (1350 lbs), 80 bhp, 118.5 Bhp/Ton -- Europa Type 46 S1 << Bhp/Ton similar to Euro Esprit S1
900 kg (1984 lbs), 160 bhp, 161.3 Bhp/Ton -- UK Esprit S1
913 kg (2013 lbs), 160 bhp, 159.9 Bhp/Ton -- Euro/ROW Esprit S1
1052 kg (2320 lbs), 140 hp, 120.7 Bhp/Ton -- Esprit S1, USA/ North American
1022 kg (2248 lbs), 160 hp, 142.3 Bhp/Ton -- Esprit S2, base (no A/C, no leather, etc)
1100 kg (2425 lbs), 160 hp, 131.9 Bhp/Ton -- S3 Esprit, pre-1985 (naturally aspirated)
1130 kg (2492 lbs), 180 hp, 144.5 Bhp/Ton -- S3 Esprit, 1985-Onward (naturally aspirated)
1148 kg (2531 lbs), 210 hp, 165.9 Bhp/Ton -- 1980 Essex Turbo Esprit, Dry Sump
1200 kg (2645 lbs), 215 hp, 162.6 Bhp/Ton -- Turbo Esprit, Pre-1986 USA carburetted
1225 kg (2701 lbs), 228 hp, 168.8 Bhp/Ton -- Turbo Esprit HCi, 1986-Onward USA Bosch Inj'd.
1305 kg (2871 lbs), 264 hp, 186.9 Bhp/Ton -- Esprit SE
1166 kg (2571 lbs), 300 hp, 233.4 Bhp/Ton -- Esprit X180R
1339 kg (2866 lbs), 280 hp, 195.4 Bhp/Ton -- Esprit S4
1339 kg (2952 lbs), 300 hp, 203.2 Bhp/Ton -- Esprit S4s
1229 kg (2709 lbs), 240 hp, 177.2 Bhp/Ton -- Esprit GT3 2.0 Litre turbo
1325 kg (2919 lbs), 350 hp, 239.8 Bhp/Ton -- Esprit V8 GT
1380 kg (3043 lbs), 350 hp, 230.0 Bhp/Ton -- Esprit V8 SE and Federal Esprit V8
There's a 180 kg (398 lbs) difference in weight between the two cars you are considering. If your first thought is, "So what?", then buy the V8.