Comptech is much more quiet than the AEM. More of a deeper growel rather than the "racey" scream of the AEM.
The Icebox is definately more practical in everyday use because it is less prone to hydrolock but it can still happen.
Installing an aftermarket cold air intake will probably take you aroudn 2 hours time if you have never done anything like this before. It is not very difficult and nothing wrong can really happen.
Make a thread if you ever need help on installing the intake.