They're just metal.If they're the plastic hooks, use the tapcons. I've blown right through a couple of those with the hilti nails.
Tapcons for sure. Not that you'll need to remove the clamp but have you ever tried pulling Ramset fasteners?
I've tried pulling them. They rip a big 'ole chunk of block right out with them. I had the same happen a couple of times when breaking them off, too, so I resorted to an angle grinder with a metal cut off wheel. That makes short work of them and grinds them flush.And I would never try to pull a ramset out....but they break off pretty easily! Ron