This is the kind of thing I buy on impulse. It's small, shiny and relatively inexpensive. I don't really care what it does. Well, OK, in this case I bought it for a very specific use: to use instead of a prussik on the headwall fixed line on Denali's West Buttress.
It didn't work well for that purpose for the simple reason that the fixed lines are large diameter (>12mm) ropes that made the Tibloc difficult to move. Its documentation clearly states it should be used be used on ropes from 8 to 11mm, so this was operator error.
It does work well as a rope clamp for pulley setups. For a lightweight ascender rig on small to medium ropes it's hard to beat, saving up to half a pound each over larger handle-style ascenders.