I know Im late... Ive had several Petzl screws in the past, they seem good enough, but im not a fan - hard to sharpen and never started well. However these were older generations. I love grivel and BD. As for these they are possibly the only screws ive never used. I just dont like the rivet that hold them together and I dont see the advantage. If you want good cheap and workmanlike try the OP ones. They seem good. Petzl makes some great well designed gear so I guess if they are the right price they could be terrific. I just dont like that rivet... Keep your eyes peeled on the BD site, they often have web specials. Good luck
I use Petzl Sonic Laser, not sure if that's what you are talking about. I like mine just fine. They are easy to rack, and very easy to fire one into the ice. About the same as the BD Express. I honest can't really tell the difference in performance between the two.