I actually think that the STi's suspension is rougher but the seats are softer so you dont feel it as much. Overall the ride is very loud, much louder than my evo. The seats in the evo are the most comfortable i've ever sat in. After riding in the seats of the Sti for more than an hour, my back always kills me, not to mention leg room in the Sti is horrible. ( the evo's cabin is much bigger) Insurance for us is a little lower on the evo (surprisingly). But however i agree with rally red and i think you should try them out for yourself.
As far as reliability, my car had 55k on it without any problems that werent fixed by warranty. I had a powersteering pump let go and my cd player broke. The reason why it blew up was because of human error. It wasnt the car's fault.