Lots of people ride Magics. They seem to work well in a variety of conditions. They are not indestructable, though. Once dinged, the low-density foam soaks up water like a sponge and it takes forever to dry out for repair. And it seems like once dinged, the problems just continue.
I have a buddy who used to swear by the Magic. He had a 9-6. Now I have two 4-9 boogie boards in my garage and no real idea how to put humpty dumpty back together again. I am not impressed with the constructuion. There is no stringer and the foam just looks cheap.
If you are pretty a pretty serious surfer and really interested in longboarding, I'd steer you toward the used board rack at your local surfshop and a log made from traditional pu/pe contstruction and preferably made on this continent.
IMO, longboards need stringers. Thick ones. That is, if you're going with normal foam and fiberglass construction, and not a Tufflite or other comp sand. The longer the board, the more leverage they create, the more likely they are to snap, especially if you take them out in good sized surf. Personally, I go with a nice three stick. Very snap resistant, and they look classy.
Re: Magic... I heard they're the most popular board model worldwide. I believe it. I've ridden a few different sizes, and they're all lots of fun. I'd recommend a high quality 2 lb. EPS core with 2x6 deck (with or without a 3/4 patch - I'd go with the patch) and 6 oz bottom.