It's a great car, don't worry. Most complaints in this forum are for older 220D's (pre 57 plate I would say), new ones like mine don't have any problems (so far). If yours is a non-Sport version, it will take you some time to get used to the long gear ratios. I had a courtesy 220D non-Sport for a few days, and at the beginning it felt weird, but after a few miles you get used to it, you just need to change your driving style. You will also feel the gearbox is not very comfortable at the beginning, but after you do a couple of thousands of miles it improves a lot, and so does fuel economy (in my case at least).
I've got a loan 220d Sport at the moment. To be honest, I'm quite impressed. I've driven a non-Sport before and the Sport seems better behaved at 70 in 6th. I like the woof factor when it's floored going up a hill. The rear view mirror does vibrate "a little" though....