i had the falken 912 on my 2005 SRT-4 in a 225 50 17.... they had a smooth/ quiet ride, good traction....
the 512 wears very fast.
if you are looking for a good tire for comfort and some performance, then the 912 is a good tire.
if you are looking for traction and an ok ride for half the price of the factory michellins then id look into the dunlop direzza Z1 super star. they wont last long, but youd probably get the same mileage from 2 sets of dunlops as 1 set of michellins
granted idk if you have an si and is talking bout the 17" factory wheels or if its a reg civic etc...
i work for sears auto center (def not bragging the job sucks, just wanted to identify myself as an experienced person in tires and not somebody guessing), if you have any questions lmk