Oooh, now we are in my wheel house.
..JBHendrix...no longer in the states due to lawsuits. Grabbed one family only. Operated on pilot pressure (600-700 psi). Closed without curl stalling. Quite frequently had stuck check valve in cylinder. Replacement cylinders were only $400.
..Caterpillar pin grabber (Miller Bug)...Grabs multiple families. Operates on bucket curl relief. Gravity and spring assisted safety lock. Bolts continually lost on safety spring. Safety bar wedges on certain families preventing disconnect. When used opposite (beating with bucket heel, or shovel digging), cylinder would football ($2200-$3700, depending on size). Prone to cylinder packing disintegrating, resulting in jamming of control valve solenoid. Early solenoids had screens on spool, and screens would jam spool.
..Caterpillar Center-lock...Operates on bucket curl relief. Grabs multiple families. Visible safety latch over stick pin. Cylinder mounted in two two bolt saddles. Saddle bolts shear ($400 aside). Cylinder lines and check assembly external, resulting in cylinder damage when saddles break. Saddle arm pivots easily changed, but occasionally on 2 month backorder. Snap rings on safety jaw links prone to loss.
..New Caterpillar "wedge style"...only have one. Bucket curl relief actuated. Hoses loose from factory, and impossible to access without unpinning from machine.
..JRB Slide lock...Bucket relief curl actuated. One family only. No safety lock. Check and relief remote mounted.
Outta time. Geith and, my favorite on 9 ton under, Strickland, to follow, as will Yanmar.