i've only got an EVOMS V-flow intake, and i blew mine at just over 50K miles -i was 175 miles out of warranty... they still covered it though (Tom Bush VW in Jacksonville, they seem pretty cool so far). I've got an AWE boost gage, normally i see 11-13 lbs of boost. with the torn seal, i only get 6-8. with the intake which greatly amplifies the normal turbo noises, i can clearly hear the valve leaking pressure once boost tries to build over 6-8 pounds. it simply sounds like the valve is open. my cel didn't come on until the second day of driving the car with the blown valve
if you don't know: the first pic shows the turbo from under the car. the BOV is on the right and says Pierburg on it, it comes out by removing the wire harness and unscrewing three 5mm allen cap screws. you can see the tear in the second shot. NOTE: the seal is not shown in the correct orientation in this picture... the lower lip should be under the black plastic cap (you'll see what i mean if you tear yours apart) refer to the pictures in the ECS tuning link above for correct assembly order... i only show it like this so you can see the tear.