I'm no guru but I recently bought myself a JTDm. Brilliant thing to drive. Are you looking for a TS or a JTD? Not sure what the others drive like, but mine (the multi-jet diesel) is a speedy little thing. I have some issues with my petrol gauge which seems to have a mind of its own, dropping insanely fast sometimes especially around the 1/4 tank mark. Have seen a lot of coverage on this issue on the forums so it seems like a semi-common quirk, most likely just the float. Other than that, well...I just checked the electronics (onboard computer) to ensure they weren't messing about. I guess the only other thing I can advise you on is to check the cambelt.