Welcome to the forum.
The difference between the Base model and the Adventure model or a model with the off road package is the off road package/Adventure model includes a front locking differential and larger tires (33" instead of 32"). If you want to off road it, the off road package is nice to have. If you're only driving it on the roads the base model will be fine (unless you get stuck in a snow drift).
:huh:
Off road package for 08 and earlier models did not include a front locking differential, they had a rear locking differential. It was 09 and later that received the front locker with a cast iron differential.
In addition, the adventure series (or offroad package models) also had different shocks and different t/cases 4:1 vs. 2.64:1 (I believe 2.64 is correct).
As for the 08, there are no known problems that would affect the majority of the vehicles like there were on the 06 models. I have a 08 lux, with the off road package, and so far have had to replace the front diff bushing/crossmember, rear shocks, radiator (all under warranty). Have just replaced rear springs due to excessive noise and they were starting to sag, but also installed a rear air bag suspension system. I have offroaded this vehicle since day one, so the limited amount of work done to it is, in my mind, minor.
Overall, they are good vehicles. Not a fan of extended warranties; prefer to take the gamble myself.