I, in my personal opinion, do not care for potting in the sphagnum moss. I tend to overwater if they're in it. I would venture to agree with the others here that it allows the growers less time spent on watering and more time on growing to ship these exotic beauties out.
Any time I buy an orchid that is packed in sphagnum, the first thing I do with it is yank it right out of the pot to get a look at the roots. I've had people in the stores look at me cross-eyed wondering what in the world I'm doing, too! I don't care... LOL... If I'm going to invest my hard earned money into another 'chid from some large, retail chain, then by george! I'm inspecting those roots!
I saw a few phals for sale at my local Wal-Mart and that's the first thing I found myself doing. Hehe... I didn't even buy any, but I was pulling the clear pots out and inspecting their roots. Orchids are like a magnet to me. I don't know why, but they just cling to me!! LOL... Hope you get a good idea of the pros and cons of the sphagnum methods. You just have to see what works best for you