Monks in this bracket are overall tuned slightly slower than many of the other classes. It doesn't mean they can't pull equal numbers, just that how they get there doesn't always fit the speed of play. They feel like they're better tuned to PvE at the moment. Play a Monk if you feel like playing slightly underpowered specs for fun, I do often and enjoy it.
MW: Does good single-target healing. Has somewhat decent multi-target abilities, but they're a bit slow. If Enveloping was a little faster, it would be viable. But as it stands, it's like a Rejuvenate with an kind of long cast time. Renewing Mist is a similar story, only in its case the slowness comes from its CD of eight seconds. If you understand the kind of fights where those abilities can work, then you can have fun. They work really well as the auxiliary healer in most situations. A good disc or hpal can solo heal in most situations, a MW really wants to be part of a healer team. If you're cool with that, or enjoy a challenge and don't mind dying, then definitely give it a shot.
WW: Like Nutbreaker said, some great damage but it comes out a little slow. FoF on the move is really nice (though it no longer has any stun component), and RSK is great. If you like being in clumped team-fights, WW can be a lot of fun. It does well in EOTS midfights where enemies are often constrained to tight spots. Does alright vs other melee on Flags in AB, but without a healer (or high-level roll-to-los play) will die to a Surv or Arms.
BM: Similar speed issues. I've only played one or two games on it in Legion by accident. In that limited experience, it seemed the toughness the spec is supposed to have didn't scale with the dmg that's coming in. It didn't feel like it had that much more useful survivability over WW or MW. The added stam is nice, but with Kegsmash nerfed all that stam is "boring stam" since you can't do much with it except stand there while you live an extra two seconds.