I feel as though the 9th generation Civic Si's are more oriented towards fuel economy and emissions standards rather than the performance side of it. The larger K24 engine has more torque which is what the American market wants, easier to drive around the city and makes the butt dyno feel happy. As far as performance wise, it's still a new engine and all, but the integrated exhaust manifold seems like a big limiting factor among other things. All in all, it's built with emissions and economy as priority, not performance.
It seems like Honda has a trend of making a good car, bad car, good car, then bad car again, etc. The 99-01 EM1 was a great car.. the 2002-2005 EP3 not so much.. the 2006-2012 FA5/FG2 was a great car again.. now it's crap again
A more fair comparison would be the FRS/BRZ vs the 2006-2012 Civic Si's instead. Let's take a look at the pros and cons:
FRS/BRZ -
PROS:
Huge ass aftermarket support
Plenty of potential
Definitely a more sporty looking
Interior seems to be more refined and elegant
Handles very well on the track with the right driver
CONS:
Engine issues? (seems like there is a reliability issue from reading about the issues on the forums)
Engine is lacking quite a bit IMO. Struggling to make 200whp is a big negative to me
2006-2012 Civic Si -
PROS:
Engine responds really well to simple mods, easily making 200whp with I/H/E + tune. Up to 240-250 with cams and other supporting mods.
Handles great when setup properly and with the right driver
A lot of space (esp in a four door)
Reliable and fuel efficient even with mods
CONS:
Aftermarket support sucks in comparison with you guys
FWD does have it's limits, it'd be better if they had the K20 in a RWD platform (cough cough Ariel Atom)
Rear suspension design is focused for comfort (I forget the actual name for it, but the shock and spring are not together and are separated)
Looks like any other Civic on the road for the most part
This is definitely a biased opinion as I have never driven a FRS/BRZ (although I want to) on the track or street, but I do one day. I own a 2008 Civic Si and track it often. I want to own both cars and have the best of both worlds to be honest.
