BigMike, I've flown them with and without autopilot fitted hydraulics off, 10 years ago now though, but can't remember any differences operationally as far as emergency practice went.
We used to mainly do running landings, but would sometimes do hydraulics off hovering (although as has been said above, I have to ask myself why in hindsight) and it wasn't that hard.
'Caution - story coming on' That reminds me of one day when I did the hydraulic test on the ground, the collective lock sprang off and we leapt into the air, stuffed around like a drunken dragonfly for a little while and landed again, wasted a couple of heartbeats but no real dramas.
Some (don't know if it's all) of the ex-military machines have a tail rotor load compensator fitted, a closed-loop type device to help with hydraulics-off tail rotor emergencies - that was after my time so I don't know if there are any issues with them.