I owned a 2001 bug eye WRX (non-sti) for some 4 years. gearbox was the main issue, hardly capable of handling even the stock power (when pushed). running just above stock, around 240 - 260 hp, i had syncromenchs replaced a few times. understeer was another problem and you'd need to 'learn' how to drive to overcome it. at the end had an engine built for excessive oil consumption but i don't really remember the exact, technical reason behind it. I was 25 at the time, living in Istanbul and was both tracking it regularly and driving quite ridiculously on public roads as well so ended up with many additional small problems as well as the ones mentioned.
I had a couple of friends who were driving STI 's at the time and they never had any of these problems. Those cars seemed bulletproof in comparison. I remember that I strictly told myself to make sure to get an STI if I ever buy one again.