I have a 33 and just got back in May from an 8 month cruise to the Caribbean. It is a great boat for a couple. I have also been on quite a few 35's and they are pretty nearly identical boats apart from the swim step in back. The 35's do have a bit better quality fittings, (ports, countertops, etc.) but not so much it would make or break a decision. They also moved the forestay forward about a foot which helps a little bit with weather helm. Some of the 35's I have seen have dorades, which I am now in the process of installing on my boat since it is nice to have the extra ventilation. Other than that there is no difference at all apart from the 35's being newer and having the swimstep. Oh, and I did install hot and cold hand shower in the cockpit - quite easy to do so dont worry about it as a real point of choice between the two boats.
I could easily have bought a 35 instead and almost did but found a fresh water 33 in really good condition. If I were you I would concentrate on overall condition of your prospective boats rather than particular features - There isnt anything on a 35 you couldnt retrofit to a 33 for a reasonable amount of money.