My favorite viewer is still SL 1.23, I'm just used to the GUI and don't really want to change. I don't like the group limits on old viewer or how prim size limits are still at 10m (don't really mind not having mesh) but still like the GUI too much to change. Someone said v3 though was customizable, are you able to customize it to look just like viewer 1.23? Because I would definitely switch over if that was the case.