My first ever locking caribiner was a Black Diamond gridlock. I still use it. But when stopped using my ATC because I got a grigri I had to get another caribiner to hold the ATC as a backup. I was thinking a non-locking one like the Petzl Spirit, but then I saw the tiny price of this one at my local gym and chose it. I know I made the right decision right when I bought it. The gate action was smooth, which was something I wasn't used to because my gridlock was in need of lubrication (by the way, If you want to lubricate any of your climbing gear like cams, biners, etc, you should put some WD-40 on it and move the thing until it goes regularly again, and then dip it in building water for 20 seconds to get the lube off). I wouldn't recommend this for belaying, but for toprope setup, personal anchors, and such, this is your best bet!