I'm more or less a newbie, and I haven't been tying long enough to be willing to spend $200+ on a vise. Originally I was tying on a piece of junk that came from a Wapsi kit. It never held hooks very well, and whether I was tying a size 12 scud or nymph(smallest I could tie at the time) or a size 2 bass fly, the hook would always be slipping. I eventually started looking for a new vise, and since I live near where Griffin is based, and all my local fly shops carry them, I decided to get a Griffin. Originally I was going to get a $50ish vise, because I didn't think it was worth getting a more expensive one. When I walked into my favorite shop one day to look for material and vises, on of the employees sold me on the Montana Pro. I walked out of the shop with it that day, and a few weeks later, I am really seeing a difference in the quality of both my flies and my experience tying them. Everything is better. It is a nice vice overall, and there is not much to criticize from what I know about vises. Compared to my old vise, the jaws are super efficient, and it is simple to adjust them. The hook almost never slips no matter what size it is. My main criticism is that the jaws can't rotate at all. I don't need a full rotary that is used for wrapping things, but I like to see the far side of my fly on some occasions. Also the clamp doesn't hold to well, but my table/desk isn't to good either. For someone looking to start tying, this would be a great vise.
P.S. Sorry my post is so long, I was trying to be thorough, but maybe I was a little extreme.