I've made this thing jump through hoops trying to find something wrong with it's performance and I can't find a thing. It was bought because my HB Sherif wasn't dealing with skinny ropes or large partners well.
I had just retired my belay carabiner, a full size HMS type, and bought a much smaller one to replace it. The SBGII works fine with the small HMS but would be easier to load and unload from a full size one. The solid stem on the belay device takes a bit of getting used to.

I was a little disapointed with the finish of my SBGII. There were a couple of little tits left over from manufacturing, on the inside of the tubes that picked at my rope the first time I used it. They were filed off easily enough though and the over all performance warrents a 5 'biner rating.

This device is very versitle. the 2 different "friciton settings" make it nice for fat or thin ropes. Also the two attachment point for increased/decreased friction in the solid handle are nice. You can even wrap the thing like an 8 if you want if sinlge roped. It's good at everything but for plan old rapelling I'll continue to use an ATC.

I have the earlier verison of the SBG II. It is fantastic.

This is an all around great piece to have on your rack. good for single ropes and double ropes skinny or fat and is not bad for rappeling just use it right or you could have to much friction.Makes your rappel tough.

Bah, there are so many better alternatives that work smoother, are more versital and don't bind up on the belay biner.

I used that device for a season before I thankfully lost it. It was a complete PITA with jerky rappels and jamming against the biner in weird spots. I personally strongly dislike the device compared to what is available on the market. To add insult to injury it even has the possibility of torquing a biner sideways the same as a figure eight (remember those fatailities that start making folks switch to ATCs) - make sure it never catches against the nose of the biner or someone could be in for a long ride (granted, this can happen with a gri-gri or any solid stem device, but at least my gri-gri seems to behave itself by staying where I want it).

By no means am I implying that the SBGII is a dangerous product, but it definately has some things *I* may not like about it. I don't like it primarily because of feel and personal preference, not because it has a extremely slim chance of having a usability problem faced by any solid stem delay device.