yep, i've got a pair of the Marquis ones, that i use on my big wb. excellent, have never rubbed. took a bit of getting used to how to fit them, but i've never had him lose one. i've had them turn slightly because i hadn't fitted them tight enough, but they stayed on. also, he can be a nervy prat but didn't bat an eyelid at the noise of pumping air in and letting it out, which amazed me. highly recommended.
Yep, used several types over the years. Happy with these, although the air was a faff to get right. I use Boa's regularly now, and have used Old Macs for years as well.
A friend of mine has some for her mare, and she thinks they are fab. The air thing makes them almost a custom fit which is very useful. They also stay put well - they stand up to cantering wildly out of control through deep mud, apparently!