I won't say better or worse either. They are very close competitor for Canon and Nikon.
I would prefer to use the D90 because i'm a nikon fan but canon fan will use 50D. So not much real answer ......
Only thing i can say is if the camera feels right for your mate then is a good camera ........
Also your previous question, i think you should take jim's idea on the tamron 17-50 f2.8
Is a bloody good lens for the price and also IS is not a must features to have to take good photo. We never have all that IS function back in the days and photo is still superb ........ I use a sigma 70-200 f2.8 non OS mkii and that have no stablization and i take good photo still. So i don't see why is a must for you. Is good if you have the extra $$$ to spend but is not end of the world for not having it .....