My wife has an '07 Si sedan. I love the overall handling for a FWD, good suspension, etc. Two things stand out:
20 minutes is about my limit in the seats. Not sure why but they hit every point on my back wrong. I can drive the Elise for 10-12 hours straight and still feel fresh.
The worlds worst fly-by-wire throttle. It just hangs after you let off the gas for about 1-1.5 seconds then starts to taper for a moment before it finally goes down. This is a programming flaw that is supposed to have a reflash available soon. It's one of those things that is so irritating it makes you want to never shift one of the nicest gearboxes I know of. How they can get it so right in the S2k and so wrong on the Si is beyond me.
Aside from those two things I LOVE the car! Awesome stereo, quick, agile, handles better than an FWD ought to this side of the '91 Elan. She has about 8,800 miles on it in the last 6-7 months and no significant hassles. Door squeak was fixed and a door trim is still loose that she forgot to mention. It holds lots of stuff in the trunk and back seats and is a nice mildly invisible (she has the grey) commuter car. Her mpg might be a bit lower than average as she seems to live in the 2nd cam. She also likes playing in Deal's Gap (tail of the dragon to the tourists) with it and it handles that road quite well.
Oh, third thing... Don't even LOOK funny at the paint. It chips/flakes/cracks if you even sneeze at it wrong. They must saved quite a bit of money when it came to being cheapskates on the paint quality...
...and yes, the first thing that happened was the front license plate was yanked off.
These were taken the night she got it.