I think they're great. My friend's horse goes in one very happily. I find them pretty nice to ride with both with and without a bit. The thing I like most about them is that they are so adjustable in terms of how much pressure is applied on the horse's head and where. I was at a show today and saw four or five of them, adjusted to different severities and with/without bits as well. My only criticism would be that the bit less strap will not stay centered and will be way on one side, but it doesn't affect the performance of the bridle.
My gelding has one and likes it, but they're not for every horse- while mine prefers it, I'm pretty sure my dad's horse would absolutely hate it. They're high-quality, well-made bridles though and worth the money (I got the Micklem Competition, which is one step up from the basic micklem)