Personally, the half hour time wouldn't really bother me because unless I'm doing several irons, it certainly doesn't take that kind of time.
If I were going for a wet bath, I'd personally go with the Tormek. I went the Jet route and while it worked, it certainly didn't compare with my friends Tormek - I tried to spend less money and now I know why. It didn't have as much power and even though I didn't really wear the stone much before selling it, my friend sharpened a whole lot more for allot longer and his stone didn't wear any more than mine.
That said - I moved away from them only because I discovered that it doesn't take but five minutes or so to re-grind a bevel on a 200 grit diamond stone. For me, it wasn't worth getting the grinder out and normally you only need to grind a single blade at a time. Anyway - my .02.