e05 had problems with breaking the shaft and is old news... there are much better turbos out there now.  blaaast turbos in my experience are very well built.  i have a blaaast stage3 on my tdi and it is fantastic.  he machines the exhaust housings and to fit larger turbines and sometimes uses different compressor housings then machines them also to fit even larger compressors.  i would either recommend blaast or for a little more money frankenturbo f23 .  i was a beta tester for frankenturbo on my b5 s4 and they were quality turbos  with minor issues that the beta testing worked out. so the current versions are perfect with even more power.