I just traded an 06 Jetta TDI for a 2010 Malibu LT2. There is no comparison on numerous levels.
* Yes, the TDI got a wonderful 44-47 mpg, but the repair bills zeroed out any cost savings.
* The Malibu's service schedule is quite modest, and it's easier to work with Chevy staff on repairs than with VW.
* Regarding size, the cars are in completely different classes.
* The Malibu is not as nimble as the Jetta, but it's ride is easier on me over long distances. It's also nice to have a quiet cabin. The TDI was heard primarily at low speeds, but at all speeds the low profile tire roar in the front (right) was an irritant, especially as tires wore down. The Malibu is silent by comparison.
I miss the Jetta's engine a lot; it was a joy to drive. I don't miss the dual-mass flywheel, nor the $1000 bill to replace a timing belt and water pump. I think I'll stick with the Malibu.