I have one similar to the one you show from Campmor, it's on the bottom of a 1L Nalgene on the side of my daypack as we speak. I have only used it a couple times to boil water, and you need to put a hunk of foil over it, or something to boil faster, and keep the embers from landing in your water, but, it works fine. The handles are longer than most other cups, so they give you an extra inch of distance from the flames/coals when you go to pick up the cup, which helps sometimes. I think mine was made by someplace called GSI Outdoor, but, there are probably several companies that market the same cup under different names. It's stainless steel, so it's not as light as some of the Ti cups. On the other hand, it's $30 less expensive
Cleans up nice, with the smooth stainless, even after being on the fire. I throw mine in the dishwasher at home after a camping trip, and it comes out looking like it's hardly used.