It's a twin screw bolted directly to the engine, your gonna get some noise.
Not when your just driving it around. However, it will howl out a bit when you get on it. (it's not that loud at all).
I run 14lbs, 21 degrees (not the KB23), T&J Stage 2 P&P heads, stock cams, 8:1 compression, a built to the hills bottom end, KB BAP, BAS, 42# injectors, ACUFB 75mm TB, 90mm MAF, CAI, 03 pumps/tank, Bassani Quiet thunder catted X & CAT back.
Heat absolutly does make a difference on this blower everybody running it will get the same results. Cold it will make much more power, hot less power.
Would I change it? NO!! No other SC will give you the kick in the pants get up and go like this SC. End of story.. To get it you don't need to kill your engine and run it up past 6K or higher.
Yes, (for those who will ask) I am the one that is using a replacement HE (Heat Exchanger) on a 01 GT. It DOES make a difference, the fans are the trick) http://www.muscle-mustangs.com/Forums/showthread.php?t=145
Last dyno run inlet temps stayed at 147/148 degrees. (some have seen it as high as 164 with the standard HE.)