I would definitely agree with Basti, that trying on as many boots as you can is best, if you have the option. If you live somewhere that has alot of shops, then that's the way to go. Any decent brand will stay dry, you'll know whether you like the flex/stiffness or not, and can decide whether a speed lacing system is for you if you prefer traditional laces when you're trying them on. However, if you're like me and live somewhere that has a very limited selection, you may be stuck buying online. If I were you I'd try on what you can, for me it was just Burton, and see if you're happy with the fit. If it fits great, see if you like the comfort, feel, features, etc., and if so, its great to buy local and support that shop.
I wanted to be able to do this, but wasn't personally too happy with what was offered. The ones I've tried weren't the most comfortable for me, and I prefer traditional laces, and such boots from Burton tend to fall too far on the low and high ends of the spectrum for me, at least of what was available. I went with Nike Vapens due to the great reviews I had read about Nikes and how satisfied I had been with other Nike products. The advantage to them, or other shoe brands (DC, Vans, etc) is they tend to fit true to the size of their other shoes, once broken in. I went around and tried on a few pairs of Nike shoes, and found the smallest size I could fit that wouldn't cramp or constrict, and got boots in that size. If you go with Nike, do note that the boots will feel too tight when you first get them, but once they're packed-out/broken-in, they'll fit almost exactly like basketball shoes in the same size. So if you find a size of Nike shoe that fits your foot like a glove, then its a pretty safe bet that Nike boots will be a nice fit. I personally find them packed with useful technologies that makes them feel super comfortable all day, honestly just like a pair of sneakers.
However, that is just my limited experience, your results may vary. As I said, I would definitely recommend you try on a number of brands and buy boots in person. But I live in South Carolina, where places that have even seen snowboard gear are few and far between. So if you're like me, then buying a brand that makes regular shoes you can try on would be wise, just get them from a place with a great return policy (got mine from Vertical Urge, though I have not had to use their support). And if Nikes do fit you, then I can't recommend them highly enough!