Well, I've had pretty crap luck with doing this.
First up, a lot depends on the logo/artwork you're using. If it's detailed at all, it's not going to work - at least that's been my experience. My logo here:
came out okay for the most part, but on four different stencils, following the instruction to the letter (I even have a darkroom with a red LED light to set it all up!) the hops underneath come out as an unidentifiable blob.
The real issue, though, comes from glasses. Most glasses don't have a nice flat (or even curved) surface to use. So you need to adjust your artwork to take into account the warping that a pint glass will produce. If you etch something, say, 3" wide onto a pint glass, it'll look like it's bulging downwards, since the stencil follows the tapering of the glass. I tried this on pilsener glasses too, since the Dollar Trees around here don't seem to carry the normal glasses anymore, and there's no way to get the stencil material onto the glass because of the curves.
Also, don't know if anyone else who's tried this has had the same problem, but the second time I tried to use the Armor etch, it was suddenly filled with little pebbles of dried cream, despite me KNOWING I replaced the cap immediately and tightly. It makes the etching process a lot messier, since those pebbles obviously don't work as well as the more liquid parts of the stuff you're applying.
All in all, I'm really disappointed with the way it turned out for me. I'm not saying it wouldn't work out for others - far from it, and the OP's glasses look awesome - but when I think about how much I've spent on trying to do this:
Glasses from Dollar Tree: $36 (12 standard pint, 24 pilsener style, since they stopped carrying the regular pub glasses)
Armor Etch cream: $16 shipped
Stencil Pro: $32 or so
Transparency sheets: $12
For not much more I could have gotten three dozen professionally done glasses from bargainmugs.com and they'd look a LOT better than the messes I made!