I have a 14 bore rifle and would prefer a 16 bore, I think. I've shot my buddies 11 bore and it's more than I like - both in recoil and trajectory. The 14 and 16's shoot more like varmint rifles in comparrison.
A 16 would be the ultimate for North America, I firmly believe - although I do like the way the 14 bore 'crushes' moose. 165gr. 2f works. In the 16 bore, 145gr.2F would do a very similar job - of that I am also certain - and kick less as well.