I've seen some mixed performances with the cheaper winches, but I can't speak for their Battery, wiring, etc setups that those guys had. My guess is they weren't working too hot because they cheaped out on the rest of the setup.

I use a Milemarker 9k and a battery that might weigh almost as much as it does. No problems yet - I winch with the motor off though when recovering others, works great.

1999 Mitsu Montero - Crappy Weather
1992 Isuzu Pickup - Zombie Apocalypse
2008 Saturn Sky Redline - Nice Weather