My posts on Moxon vises are among the post popular I have written, and understandably so. I have found mine to be absolutely indispensable, near the top of my list of essential tools. I can't recommend them highly enough to you. There have been some developments in the past year, so here's an update.
Several major manufacturers have new or revised offerings. Benchcrafted has significantly changed its design from one in which the screws protruded through the wheels to the front to one in which they are attached to the wheels and protrude through the back. It's 24" between the screws and the maximum opening is 2 1/4." A complete vise with 1 3/4" jaws is available for $399 and a hardware kit is available for $199.
Lie-Nielsen has a new offering. Based on its chain drive twin screw shoulder vise, the company's dovetail vise is 18" between screws with 2 3/4" maple jaws. According to the company, its maximum capacity is 6" and it is available for $385.
My vise cost approximately an order of magnitude less, a really dramatic difference! Is it worth paying ten times as much? That's a question woodworkers can only answer for themselves, but for me the answer is no.
I think the new Benchcrafted design is an improvement, but I still don't like the big iron wheels on the front for my saws to find. Think about cutting half-blind dovetails, for example. I prefer my wooden handles for that reason. Another disadvantage of the Benchcrafted design is its very narrow maximum opening, which is OK if you only use it for dovetailing, but I have used mine open to 6" on a number of occasions and like the versatility of being able to do so.
I find the Lie-Nielsen offering to be the better of the two. The steel on the front is much lower profile, and therefore safer in my opinion. For the reason already stated I like the much greater maximum capacity and think it would come in very handy for many woodworkers. There is also the chain drive feature, which could be handy. In practice, I find that I am usually just loosening and tightening one of the screws for repetitive operations once the other one is set on the first piece. I suspect the vise is quite heavy due to the chain drive and very thick jaws. It also precludes skewing the jaws, although in practice I have never wanted to.
I think that the acme screw I bought and made wooden hubs for is a great cost-effective solution. I would still like to have a wooden screw version someday, but that won't happen until somebody makes an affordable, high quality tap and screwbox or somebody begins offering an affordable pair sized appropriately for a Moxon vise.
The major issue I encounter with my version is that I sometimes want to clamp pieces in the top half of the jaws, which makes them rack considerably in the vertical direction. This product isn't long enough so I have been thinking about making something similar.
You may recall that this is my only vise and that likely affects my preferences. I keep intending to install a bench vise on my Nicholson bench, but I have become so accustomed to the many ways to hold workpieces on my split top bench that I have never felt a compelling reason to do so. You get used to it and it is almost second nature. When I watch Paul Sellers work almost completely in his vise for virtually every operation, it makes me feel like I must be doing it wrong, but I seem to be able to do everything he does without a vise. Maybe a better way of saying it is, I don't feel that I would do any better if I had a bench vise. I have gotten as far as deciding that, if I do install a bench vise, it will be either the Lee Valley twin screw vise installed on the end or a leg vise with one of those beautiful wooden screws from Lake Erie Toolworks. The former seems more practical and the latter more aesthetically pleasing.