I personally have owned and modded both. If you want something that you can mod for cheap, go with the GSR, if you want to go for power, go with the prelude.

My prelude had the SiR S-Spec engine, and like my97lude said, it would rape a ITR. I would not go with a prelude SH. The ATTS adds about 250lbs and does nothing that an aftermarket LSD or a jdm LSD tranny wouldn't fix, without the weight. It is also not a good idea if you plan on adding more power. the ATTS units have a reputation for failure under additional power. anything more than about 240whp and dont expect the ATTS unit to last more than 10 or 15k miles.

I currently have a GSR and parts for the engine and body are much cheaper. My only problem is the extreme lack of torque compared to the H22A.