Not a fan of the M200 not because I find it a bad revolver, there's just better 4 inch revolvers out there that you can get in .357 Magnum instead, specifically Charter Arms. Yes, you'll pay $50 more for them at the least, but we're talking a better made revolver that weighs less, shoots a much more powerful round, and has better sights. The only thing it lacks is the 6th shot and I don't see that as good enough reason to buy the M200 over a Charter.
As for the snub M206, it is a good snubbie. Heavy for carrying and it's clunky when reloading, but the trigger is very good. I had been down on it recently, but after shooting it a week or two ago, I can't say that anymore. It's a lot better than I gave it credit for and now I can't say a 5 shot Charter Arms you could get used for about the same price is a better revolver. It's a lighter revolver better for carrying and that's all.
If all this will be is a boat gun or plinking gun, the M206 will do that just as well as the M200.