Works, but not the best
Well, she works. And for the price, it's hard to complain. Does everything the reverso and xp-guide can, and the horn is kinda handy if you're lowering a fat dude.
However- the spring doesn't do anything (is removable, though) and with or without it the device tends to jam on the rope pretty hard...which miiiiight be safer, but also is a big problem when someone's leading. throwing out slack just isn't going to happen here, and rappelling's going to be a bit slow and jerky. Also, it's a pretty big piece of metal. much larger/heavier than my old xp (which got stolen, hence my switch to this)
that's my two cents. works, but not particularly smoothly