Often, i struggle to answer this, but today my friend collection a 200sx, and i watched him checking his turbo for play, it took about 45 mins of undoing crap, clips rubbish nonsence for him to get to it, then he removed his front bumper which unearthed so much orange rust and ****!.
I think one of the most important things for me and 5 gtts is the fact they are so small and therefore managable, i often feel i suffer from ocd when it comes to cars, which is a very bad things, but at least with 5 turbos its possible to solve the craving of making everything mint quite easilly.
Also for me its simply because nothing can beat the cheeky look of an r5 coming around the corner of the road, barely taking up 1/4 of it, they always seem to bop along as though there on chopped springs, and then when you hear them come on boost it just seems so wrong... OH man i cant wait to get back on the road in mine !