Do you guys ever use Max Revives?

Yes, when they take down my Blissey (almost everyday, she's such a magnet) or Snorlax for example.

when I m down on potions

Yes. I use them on Snorlax, Blissey and occasionally Vaporeon.

When prestigeing up to defend a gym against an attacker. It's possible to do this alone if the attacker is a low-level n00b but it's frikking hard and you got to be fast, no time for Revive + Potion

I use max revives for big tanks like Blissies, Snorlaxes... or when we battle and need quick revive to jump in the battle.

I use them even to heal a Parasect that I could heal with a purple potion. The only reason: to free space or because I'm low on other potions.

I use for Blissey and Snorlax.

When you need to clear space in inventory.

To reward an especially heroic prestiger/attacker!

HUH???
It's a one shot total heal! It's the only thing I keep in my inventory. I throw away all other revives to keep my bag open for other stuff. I only keep max potions, too. All other potions are just space grabbers.

I have 20 Max Potions and 20 Max Revives. I never use them but I like to have them XD

I only use max revives - I recycle all of the normal revives I get to make more space in my inventory for balls and berries.

to be honest i use revives and potions before i start using max revives just for inventory management purposes. takes 2 items out of your backpack and you get to keep the more efficient max revive.