The hand guard felt fine and the width was not bad at all. For me it was the controls. I am used to to the 870 and running something new was like driving a rental car. I had to second guess what I was doing, it didn't feel natural.
I just went and tried to stick 7 (2-3/4") shells in it, 6 in fully, #7 half way and that's it. So, yes it truly is 6 rounds in the mag only. My 870 has a mag extension and is the same barrel length and that is also 6 only. (Maybe a Remington thing)