I had an ebay turbo kit on the civic.
Worked damn great!
The worst part was piping it.
After a good 8 months of beating the crap outta the car every day, the b16 finally gave.
But the ebay t3/to4e was still good! No shaft play and still works!
The ebay blow off valve and wastegate worked great. The bov was by no means the fastest reacting bov, but still worked ok. The wastegate never gave me any problems whatsoever. And as of the manifold, well, it was a cast iron manifold and worked just fine.
There's my experience with ebay kits. A damn fun run for the whole $600 dollars I spent on that kit to blow a motor up!