Did you really avoid driving the 35i because of not wanting to be tempted? Or are you really trying to keep costs in check?
Sorry, the 35i is just the better power train option...period. I would have compromised on some other techie options before I checked the 28i first.
I just went through the same process, but I drove them all. 1's, 3's, X1's, X3's and no matter what I drove it had to have the six cylinder. In a BMW there is just no compromise.
Seems silly to not test drive something just because you know it might sway you. Head back to the dealer and grab they keys!
Just my humble opinion!