Engines are just as reliable as most subaru engines, its the tiny turbo's that chew themselves to pieces if they see to much overboost. Most sellers probably don't like strangers doing this but when test driving do a pull most of the way to redline to make sure the secondary does in fact work as it should.
And with the simple vacuum hose mods by marky and rosssub the VOD region can be greatly reduced giving a completely different driving experience. Also if you want to get it tuned in future you have to get a rev d, a-c make tuning quite a bit more difficult