[Grumpy]

Depends what you are tearing off. I find pitch forks to be the quickest for removing shingles. Then come back with one of those home depot tear off tools with the teeth for popping out all the nails very very quickly.

For tearing off low slope it's a cutter and a wheelbarrow, and sometimes an axe for flashings.

 

[Grumpy]

We found shingle eaters are the best for shingles so we can remove nails as we go save you from coming back, we use wood forks for wood shakes.

I hate using them for tearing off shingles personally. Yes it seems like less work so you don't have to go back and pull nails, but I find we tear off more per push with the pitch forks and it's not at all that time consuming to follow with the eater to get the nails. Nothing's worse than constantly smacking the nails with the eater when you're trying to rip.

 

[Grumpy]

We use the same angle grinder we use for cutting our reglets, but change to a metal blade, sharpen, works ok. Soft Chinese steel = disposable tools.