I like Pegasus and Professional's Choice SMBs; I've borrowed a pair each from friends for my barrel racing mare. But what I have now is called Performer's Choice Sports boots -- they're like a crossbreed between the two. They have only two pieces of velcro, like the Pegasus boots, but are constructed (material wise) similarly to the SMBs. I've never had a problem with them retaining water too bad... 'course the only time they get sopping wet is when I dunk them in a bucket of water for cleaning. They're very breathable, and I've never had a problem with them slipping or getting dirt under them or anything. I've also had them on nearly all of my horses, from my delicate-boned 14hh mare, all the way up to my big-boned 16hh gelding, and I've not had them rub in the least.
Here's a photo of them, for reference: http://www.chicksaddlery.com/Merchan...0001/SMB29.JPG