I own a 335d so I'm a bit biased. But I took in my e46 for some repairs and they loaned me the 335d. I was just blown away, literally. The power is phenomenal. I looked at what my bill was going to be for my repairs, traded in the car and bought the 335d. I was that impressed.
In regards to your gf situation, I don't think you can really answer that question without going in and test driving both. If you still don't have a clear answer on the performance issue then look at all the other things that make a difference and decide on those concerns.