[TurboSE]

I drove both before I decided (S14 was 5-speed, S13 was a hatchback auto) so my comparison is kinda apples/oranges.

Both were pretty much stock, sway-bars on the S13.

The S14 felt "bigger" I guess is the best way to say it, I felt like I was driving a larger car than I really was. It also felt a bit clumsier. But they were really similar. When I started shopping my list of preferences was:

S14 Kouki
S14 Zenki
S13 Hatch (S15 conversion because I hate flip-ups)
S13 Coupe (didn't like these at all until I saw one with Bricks)

I ended up with an S13 coupe for the following reasons:
Price - clean, unmolested S14's are expensive (to me anyway)
Stability - coupe vs hatch, coupe needs less reinforcement
Year - (big reason) in Pa, my 92 just gets a gas cap inspection vs. a 95+ getting a real smog check (Swapping an RB26, I don't want any nosy mechanics snooping around if they don't have to be).
Difference factor - I see a fair amount of hatches and S14's...not too many S13 coupes

I know this isn't exactly what you wanted, but the nice thing about the S-chassis is that aftermarket support is so strong, if there is something about yours that you don't like...someone has a way to improve it.