In reply to ilovetoclimb: The stop is a better heat sink (important on long abseils), the rope can be loaded/unloaded without taking the device off the harness/karabiner (vital when passing things like rebelays), has more options for increasing/decreasing friction (important on thin/muddy/worn ropes), is more robust (the handle/lever isn't particularly strong on a Gri Gri), etc. Basically the Gri Gri is fine for slopes, occasional abseiling, belaying, lowering etc but isn't a serious bit of kit for serious abseiling use; we've taken them out of general service within our cave rescue team. I do like my Gri Gri but only seem to use it for self-lining if I'm aid climbing. That's just my opinion as a caver, rope access bod & fair-weather climber.