I sincerely hope that the lack of a dipstick isn't really a factor in your decision.The 335d has one.
At the moment it's a toss up between the 335i and d for me... hmm... dipstick or manual transmission?
GAHHH!!! TOO MUCH PRESSURE!
newc6, tturedraider is right, dipsticks went the way of the dodo for the 2006 MY on the E9x 3-Series (the coupe/vert still had them in 2006 because that was still the E46). I'm not as familiar with the other Series but all the new N engines do not have them.