Gee, reading some of these posts you'd think the 335 was made by Ferrari. Reality check, it's a 3 SERIES BMW!
On paper, a 335i is obviously a lot faster. Similarly, a 328 MT is faster than an AT. However, we don't drive on paper, in the real world, roads are wet and have corners, lots of them.
I doubt a 335i is going to perform any better than my 328xi given my commute has very few straight runs and lots of corners, plus where I live is wet or a good 3 months of the year.
Similarly, a 328 MT may feel faster due to the driver interaction, in reality, unless the driver is hitting the optimal shift points (which he probably isn't) it isn't any faster than an AT.
At the end of the day, for practical purposes, all these cars are going to have similar performance. They are all 3 series, i.e. entry level sport sedans, they are not performance cars by any stretch of the imagination, hell, much of the world uses them for taxi's!
Don't get me wrong, I love my car but see it for what it is, a nice daily driver. Driving ANY 3 series is no reason for arrogance, they're dime a dozen on the roads.
Ultimately, buy what you can afford and what offers the best value for money.