We starting skating after our third season snowboarding.
I will say that some aspects of skateboarding will totally translate and cross over to snowboarding.
If you do park/pipe, skating half-pipe, bowls, transitions, and carving cement bowls in the summer will cross over to half-pipe snowboarding.
The balance from street skating crosses over to ollieing and doing boxes and rails on a snowboard.
For me, I saw a big difference in my snowboarding after my first season skateboarding during the summer. I was able to do or at least try to do things I was not able to do before on a snowboard. My riding was more fluid and even though I had not snowboarded for months, it felt as if I never stopped.
We did not like longboarding.
But we really like skateboarding the summer. It's fun. Skateboarding is very challenging and remember that when you fall you are going to slam on cement.
However, when spring starts, the snow starts to melt, and the ski resorts close, we look forward to skateboarding. This actually reminds me that I probably need new bearings...