I trust your judgment. I have seen each of them play once (last night), and just felt that Fox was slightly more poised and creative offensively. Not a lot of defensive prowess that needed to be shown given the competition last night, but that may be where Marino shines.
You are right. Having young, talented, and especially, mobile, puck-moving D is incredibly valuable. Vesey's speed was very much neutralized last year because the D could not hit him in stride on the rush and thus he had to come way back to get the puck.
I like this team more than last year's. Lots of hockey to play, but more balance, much more to offer on the blue line - it will be interesting to see how this team handles adversity (through injury or when someone hits them in the mouth). There is great depth though, both at D and F.