An umbrella is probably the first modifier most photographers gets, and rightly so. They’re cheap, dead easy to use and produce nice, soft light. Personally I have two of these highly collapsible umbrellas from Westcott and I don’t see any reason not to have them. Though I usually choose softboxes for my main light, umbrellas still has their uses.
I don’t really think it matters much what brand you get when it comes to umbrellas, they should be more or less the same. If you plan on using it a lot outside though, I wouldn’t recommend this particular model. Instead I would choose a sturdier type that doesn’t fold down quite as small. Just consider where you’ll use it and how much you value staying as portable as possible.