I installed mine this morning (Sunday 2/15/09). It took me about two hours by myself. Thankfully, I have a TV/DVD in the garage and threw on a Futurama DVD as I worked.
Anyway, the install is not that bad. I just took my time and went through everything as carefully as I could. Yes, it gets tight at times and you need to wedge yourself into some interesting positions to get at the hose-clamp holding the inlet to the turbo (both stock and Cobb).
The now-infamous vacuum hose from the wastegate did not give me one iota of a problem - just loosened the tiny hose clamp and pull straight up and it came off fine.
The one problem I ran into had to do with the hose that comes off of the Bypass valve (I have the RKM/HKS SSQV) and connects to the bottom of the turbo inlet (underneath the air intake).
I have the upgraded recirc hose from Street Unit. It's a lot beefier and thicker than the stock hose and it was a complete b**** to get into the Cobb metal fitting, but a good amount of grease and some muscle got it on.
Once everything was hooked back up and I took the car out, it's immediately apparent that the turbo spool is instant. With my Cobb intake, it made the turbo sound pretty audible when the engine was under load - usually about half-throttle at 3,000rpms and up. Now, with the inlet, turbo noise comes on at any throttle load. Tap the throttle and you'll get a nice little woosh - even right off the line in first gear.
Recirculation noise from the bypass valve is also a bit louder and deeper.
The butt-dyno indicates a slight bump from a stop all the way through the powerband.
All in all, a good mod for $160.00 and a couple hours of getting my hands dirty.