As others have said try to get a V8 with the 6R60 - it's a good combination.
Having said that - it has it's problems. Then again - what car doesn't?
I bought my 07 in 08 with 17K miles on it - I'm at 140K right now. I think I learned more about working on cars from this thing than I have from anything I have ever owned.
- I've replaced the radiator twice. It isn't a simple process.
- I've replaced every wheel bearing at least once - some twice.
- I've replaced the passenger side exhaust manifold twice - it needs it again right now.
- I've had to fix the issue where the climate control only goes to defrost.
- I've replaced several climate control door motors.
- I've replaced a follower but fortunately I caught it before it got too bad so the cam lived.
- I've been through the transmission shudder which was solved by changing the fluid twice.
- I've been through a plug change which actually worked out well - the tool I bought in case they broke went unused.
- I've put new hood struts on it - the joke was they wore out because the hood was open so much.
That's a high level overview - I haven't listed maintenance like brakes and filters and diff fluid changes and such. I have done new struts on all four corners but I consider that maintenance. I have done everything myself - if you can work on it it's not expensive.
Having laid out the normal bad points - here is what I haven't done and don't have any reason to do currently (I list some of these because they seem to be issues from what I've heard that I haven't had).
- All my coils are the originals
- The starter hasn't been changed although the alternator has.
- Cam phasers and all other timing components haven't been touched.
- Injectors are all original.
- All half shafts are original.
- Fuel pump is original.
- U joints on front and rear driveshafts are original.
- Transmission is original - fluid and filter changes only.
- No work on any of the diffs - fluid change only.
- The throttle body has never been cleaned and the intake has never been off.
- No engine sensor has been changed.
- None of the wiring has been an issue (this is a common problem).
That's mine. I can say it literally runs and drives like it did when I bought it in 2008 - except for the exhaust tick on startup. Again - I bought it fairly new - only a year old so it lived it's life basically under my control. Buying one at this point you don't know how it was treated and how it was treated makes a big difference in what issues it will have.
So good luck - they are good vehicles but like everything else - in the wrong hands they can be ruined.