I've only ever spun the T67A, but that was fine. You had to be very careful with aerobatic weight though - and no more than the precisely calculated fuel state depending on crew weight was ever acceptable. Spin entry and recovery seemed entirely benign.
The Bulldog was normally OK, but on occasion they could be a bit slow to recover from a normal spin. I'm convinced that was probably because the fuel was out of imbalance limits... You were supposed to ensure that there was no more than a 3(?) gallon imbalance and students were encouraged to make sufficient checks to ensure they stayed inside this limit. Trouble was, the gauges were utter cr@p and weren't really good enough for the task. So your carefully balanced fuel could, in fact, be outside limits without you knowing it - and that certainly made a difference to spinning! One QFI castigated his student for poor spin recovery technique - this surprised me as he was normally pretty good. I flew the same a/c a couple of days later; we flew with 'both' selected and the ball firmaly in the middle, but the gauges showed one side coming down quicker than the other.... We didn't touch anything, but landed and had the contents checked during the refuel - both sides took the same amount, so they must have been equal in the first place. Made a note in the 'spinning' student's record that the delayed recovery was probably due to a/c unserviceability and NOT his fault!
Why are light a/c fuel gauges such utter rubbish?