I have a '04 2500 HD 6.0L and am considering a tune from Nelsons. What problems/risks are associated with installing this, in regards to warranty or mechanical problems.

This is a everyday driver, and don't want to install something that will make it run rough or cause problems. Also if it goes into dealership for service, will they clear the program out??

I've read all the forums about how well these tunes perform, but would rather stay away from trouble. Also where are the best prices at for these?

Thanks, Jason