Personally I've mixed views on it, but only used for relatively short pitches to date so limited experience. I find the handle easier to use and control, seems as smooth to use as the old stop. Cant make an assessment on wear. I'm using it with the new frieino grab with mixed views in that it snags on things occasionally and pulls the rope over the side plate of the stop so is bound to make it wear quickly; but that was the case with the older version. One of the issues I have with it is in use I find I instinctively end up with my elbow out to use the handle which is a right pain in a snug pitch, just something that needs re-training...
I think the main issue for me is the change in EN standard, in that its EN15151-Type 5. That standard is for a belay device, but critically the "Type 5" classification relates to it being a belay device for single person abseil only (i.e. not belaying a climber). The older version with EN341 which was a rescue descender so could abseil with a 2 person load. It wasn't rated for belaying although was used (probably still is) by many. There was a bit of a mix up by Petzl when they translated the instructions of the old Stop from French to English and used the term "belaying" in their instructions but the device was never tested or designed to be used for belaying. The same is true for the new stop (despite what was written in a recent review in Descent). So for work I'll not be using the new stop, it's just not versatile enough. Petzl have confirmed this. Incidentally they also confirmed you can use the new stop to rig a Tyrolean.