Not sure why rule and cool dill are knocking these guns. I have no experience with the Winchester SXP, although I have a decent amount of experience with its predecessor, the 1300. The 1300, compared very well to the 870 and Mossberg 500. It was smoother than either, and just as reliable in my experience.
I haven't owned a Nova, but have shot a friend's plenty. It was a solid dependable gun. For ergos, i preferred the winchester, remington, and Mossberg. But ergos are very very personal. It is a nice pump gun. I had thought that with a 3.5" chamber, i'd be more likely to short stroke, but I didn't have any problems at all.
If either of those choices were all i had to defend my home, I'd feel well protected.