Most of the time i use 3.5's. Its like a mental block for me. I used a 10 ga for 4 years too, before my cousin got back into hunting and was ready for it back. I just can't bring myself to shoot 3's. I feel like im leaving some punch in the bag.
Im also 6'4 250, and think bigger is always better. I couldnt bring myself to shoot less than 70 lbs either. Just my preference.
I think its just because i am so big, the only vehicles i have ever owned have been full sized as well.