Ah yes, the TC33D vs the B2910 question. This question pops up often. Generally, a search of the NH, Kubota, & General areas should reveal many questions and answers on this comparison. I know this, because, I had same decision to make 6 weeks ago. I chose the TC33D. It was a heavier tractor, fit me better, and had a 7 gauge steel MMM. TC33D with MMM is about 800lbs heavier. I personally thought the $1000 extra that the NH cost was worth it. Many say the L3010 is a closer match to the TC33D, but not many people seem to compare these models. I didn't this comparison either, the L series seemed to be too big to me. I personally think the L3410 is a closer match due to it's increased weight. But then again the TC35D is a closer match to the L3410. It the apples & oranges thing. /w3tcompact/icons/laugh.gif
As far as stability, it's a question of wheelbase & tread width. Both should have a comparable center of gravity. As far as maneuvability, both should be about the same unless you opt for Supersteer on the NH.
Both are popular tractors with TBNers, and I don't think you would go wrong with either, just pick the one the fits you better and which dealer you feel better about.
Here are some numbers:
Model, Wheelbase, Minimum width, Weight, Loader breakout
B2910, 65.6", 53.8", 1763lbs,1618lbs
TC33D, 63.0", 54.3", 2474lbs, 2344lbs
TC33DSS, 72.0", 54.3", 2588lbs, 2344lbs
L3410, 65.7", 56.5", 2800lbs, 2557lbs
TC35D, 61.3", 73.5", 3252lbs, 3186lbs
TC35DSS, 61.3" ,81.0", 3421lbs, 2929lbs