I started off on ski's. I also played hockey my whole life and I caught on to skiing really quick. I was going down black diamonds within a couple hours of my beginner lesson. Controlling skis is a lot like skates. Both feet move independent of each other and you have an inner and outer edge. For me, I enjoy skiing, but I will never be really good where people on the lift look down and are amazed. However, I get down all the hills I want to (excluding moguls) no problem.
I decided I am going to be as good as I need on ski's so I started to snowboard.
Snowboarding for me has been WAY tougher to learn, but from what I hear there is a steep learning curve, but once you catch on you can get pretty good.
Skiing is easier to learn, but harder to get real good at.
Snowboarding is hard to learn, but you get better quicker is what I am told.
I can vouch for the learning part and will let you know about the latter.