Easy to place, stays put. Everyone has their favorite set, and these are mine. The groove makes a tangible, positive difference occasionally, and is inconsequential at other times. Wallnuts don't make every other set obsolete, but the groove is a nice touch. I climb primarily on southeastern sandstone and when positioned carefully the groove seems to make it stick on the knobbly bits in cracks and move around less while the rope slides through. I have the habit of giving it two or three good tugs to set the piece and I haven't had any special trouble removing them, nor has my climbing partner. Even so, buy a nut tool. You'll need it now and again for any brand.