I don't think 38's would fit, even with a 6 inch lift, would they? I think the full 6 inch suspension lift would be required for 37's and then it might take a couple inches of body lift also. Maybe I'm mistaken. Also, although there is a 6 inch lift for the Titan, I did not know there was a 6 inch lift available for us yet, given the special requirements needed for our independent rear. Is there?
I know there is a thread hear suggesting that a 6 inch lift is out for us, but it does not seem to work in its present form for a 4x4 (why lift if it's not 4x4?) and I'm a long time off-roader who is unfamiliar with that company.
Given the wording of the question, I can't vote. But if you were saying choosing a modest lift and going to say, 35's versus, lowering and big wheels, I'd go with the lift. After all, I sort of made that choice when I chose the Off-Road package. Wouldn't make much sense to get that package and then lower the truck. I like the dirt!