I skied for years, and am a much better skier. However, a friend convinced me to try snowboarding two years ago, and I haven't looked back.
I would say moguls are definitely easier on skis. That said, I uckfaying hate moguls. They're slow and they're painful, even on skis. I really do appreciate the level of skill involved in doing them right, but they seem to me as more of a personal challenge, and less about fun. Also, they really mess up the difficulty ratings of the runs. A blue square suddenly becomes a deathtrap because the groomers decided to mogul it that week. Then there's the black diamond that becomes a complete bore when you avoid the moguls. I've always been more about finding interesting and varied terrain than about patterned bumps
Skis are safer - you will never convince me otherwise. You have more edge to use, more control, and you have safety bindings. If you're worried about injuries, skis are the way to go. I have never injured myself as badly on skis as I have on a snowboard, even when I was just learning to ski.
I can't put my finger on why, but snowboarding is just a lot more fun for me, even though I feel I'm far more likely to kill myself doing it.
