compression test will tell u how the engine's internal is, based by how u or prev owner maintained the car, if it has been abused etc...
my B18CR after 5 years of driving and tracking (48k since i got it installed, guesstimated 100k total, appro 6 track days) i am still running 205psi all across, compares to 210psi from day one, not too bad!?)
btw, we saw u (xelloss) this sunday about 5pm at Gilley and Rumble while test driving derek128's SiR...u live in my area as well?