TP Underdrive Pulleys

[GasPasser]

I just got my custom tunes and they are really nice. Bill definitely knows what he is doing. But it's time for the next upgrade to the truck. First on the list is a set of underdrive pulleys from Troyer, I just have a few questions.

I've read a little about adding them to the truck and most say you don't need to do anything other than maybe increase the idle RPMs by about 50 or so if the battery voltages drop at all. I've read that with a custom tune this probably wont happen because the tunes have already most likely increased this. Is there anything else I should be concerned with needing to have changed in the tune?

How much benefit will I get out of them? Basically are they worth the money?

Did you guys notice any difference in pick up when you throttle it? Low RPM or High RPM differences?

At the very least I'm going to pick up a higher quality serpentine because to get rid of the belt squeal when I'm pushing it, but I'd like to go all out if it is worth it.

Thanks.