Brake question with Chevy IBC

[Campy]

Towing our 5th wheel with our "new to us" 2008 Silverado truck with the IBC (integrated brake controller) I find that I have to max it out to 10 to get any decent braking at all. On our old truck with a Tekonsha controller we only had to have it set at 4.7 and had good brakes. Are the IBC's just not that good or should I adjust the brakes on the trailer tighter? Right now the brakes are adjusted to 8 "clicks" loose.