SO far nothing has gone wrong (knock on wood). Just regular maintenance items such as fluid changes, and regular inspections keep it in tip top shape. The leather seats of my R/T model are holding up well considering they're eight years old!
One thing that's ongoing (especially now that its winter time) is I have to constantly lube the rear lock mechanism to keep it from sticking open. Otherwise, when I open the hatch and go to close it - it won't latch; it'll bounce back up about 1" then look like its closed, but its really not. This is more of an inconvenience and with the vehicle being driven in harsh winter conditions and being eight years old, I'm surprised I haven't had more problems!
The R/T makes a great touring vehicle. If you live in flat grounded areas with no hills then the R/T might seem overkill. EPA rates it at 12/16 (old ratings) and I average 14.4mpg with 50/50 driving which is acceptable, even considering that I romp on the throttle occasionally. The 3.92 axle ratio puts rpms justa touch over 2000rpm at 60mph. More modern SUV's are around 1600-1800rpm at the same speed. So if you drive a lot in flat areas you'll want an SLT with 3.55 axle ratio. However, performance will suffer.
The A pillars are thicker than normal, which can be a hindrance in tight corners where there are a lot of pedestrians or things going on to keep track of since you have to move your head more than usual.
I'm a big guy (6'3" 245lbs) and find the cain size is just right. I don't like too much space and I don't want to feel squished either. When going over rough roads where the trucks suspension rebounds a lot I have to put the power seat down all the way or else my head bounces off the roof ever so slighty. Its just an annoyance.