basically any warn is a great winch and can't go wrong with them.
I just bought an xp9.5 for $930 on amazon.com I thought it was a good price for it
Anyway, I found this information on another board that was very interesting compareing the xd9000i and the m8000.
The Xd9000i, X8000i, and M8000 all share the same motor and basic gear mechanisms. The gearing is slightly faster on the 8000-lb winches, which is why the line speed is slightly faster. Maximum current is reached when pulling at rated capacity on the last layer of rope that is wrapped around the drum, with the drum almost stalled - that's why the higher gearing pulls the extra 20 amps.
The M8000 and M6000 share the same gears and mechanism, but the M6000 uses a smaller motor.
In different years, Warn has switched motors and motor suppliers, so what I said about the motor being the same applies to winches manufactured in the same year - it doesn't mean that motors of all years look the same.
The differences aside from the gearing is that the XD9000i and X8000i have the solenoid pack integrated whereas the M8000 uses the seperate solenoid pack - requiring the mounting bracket when you mount it to the winch, OR a pair of large diameter hose clamps that fit around the motor. But some low profile bumpers accept the M8000 or M6000 internally, whereas the integrated solenoid designs won't fit.
M8000's are sold both with roller fairleads and with hawse fairleads. If you intend to fit synthetic line then get the cheaper hawse fairlead since you are gonna replace it anyway.
The final difference is rope length. The XD9000i has a 125' rope because the lower/slower gearing will tolerate an extra layer on the drum while still pulling a usefull amount on that first rope layer.