Georgia Arms....my sons and I burnt a lot of their ammo several years ago when I had time to train. It always went bang and never a problem.
Bench Master foam blocks...that's totally new to me. Interesting. I'll have to look it up. The Lead Sled may have been better....but you are where I am on that I think....don't feel like dragging it to the range. I just bought a couple of bean bags. I think it may be better than the lead sled except for the recoil part and I'm old enough not to hurt and not too old to not hurt bad when hit so I'm at that golden age.