Matthew - I don't have the Grizzly, but I do have a Shop Fox quick-release, and they're identical. I would avoid this like the plague. Mine worked well enough for about 6 months, but quickly developed enough slop that the lever quick-release will now release on its own - usually at the worst possible time."Thanks for the feedback. I've been eyeing the Grizzly vise for my upcoming bench."
My new bench that I completed last fall has a Jorgensen cam-acting quick-release front vise in the face vise position. I cannot recommend this vise more highly - the machining and castings were far superior to the Shop Fox (and an Anant before that), and the cam-action quick release mechanism is bullet-proof. It's a huge step up, and costs about $70 more than the Grizzly/Shop Fox tawainese version. Woodcraft has them, and most stores stock them, so you can go compare.
Considering that even a modest bench costs about $200 in lumber (and that's the cheap stuff - maple/ash/white oak's a fair bit more), takes about 40 hours to build, longer if you've got custom features, and you'll be using it for the next few years to more than 20, spending the extra dough to get a good vise is well worth it, in my opinion.