Installed my BBK with Brenspeed tune (87 octane loaded for the moment). In a word...... EXCELLENT!!!!! You will be happy - much better throttle response and a definite "feel" of the increased power. Two comments on the BBK - 1) It's a bit of a stretch to connect the breather tube - a little more slack would be better. 2) The large clamps to attach the blue rubber coupling on the throttle body and air intake tube are not exactly top-of-the-line quality. I plan to find better ones and replace them later (that's why I wasn't too concerned about lining them up).
No whistling sound. It sounds normal to me - kind of like a big Holley 4 barrel getting romped. I had a JLT on my '05 and it sounded about the same. Of course it is louder than the stock intake system. The only time I really hear it is when the throttle plate is first cracked open and when I'm fairly aggressive with the throttle. Oh, so I guess I hear it all the time.