i have gone GT28 turbo as my motor has had alot of work done 2 it 8000$ internals i chose the gt28 as it isnt as laggy as TO4 and is still very punchy very good alround turbo street and track.. i have had a TO4 on a mildly worked SR20DET was very laggy but once on boost went very well
GT series turbo's are a much better turbo. to as u can hear the compressor wheel which is (roller bearing)still spining. when u are out of your car! sounds wicked....