Just thought I'd post my own opinion about the M-55s. I have the 285/75R16 10-ply and went out of my way to get them. I actually ordered them from the US (I'm in Montreal, Canada) and had them shipped to Champlain, NY. I then drove down and had to pay $20 of duty per tire, plus taxes, to import them. The reason I wanted the US model is they're pinned for studs, while the Canadian model is not. People around here didn't want to hear about drilling tires, so a pined tire was the only way to get studs. I also went through the trouble of hand-siping the tires, as I wrote about here:
http://www.jk-forum.com/showthread.php?t=21865&highlight=hand+siping
The siping makes the tire grip better in all conditions. The design of the M-55 also appears to expel water very well. They clean well in snow too, and even parking on the street all winter, we haven't used a shovel once. I haven't had a chance to use them in mud yet, but Spring isn't too far away now...
Supposedly they wear really well, so I was afraid the rubber might be too hard for winter. The siping and studs probably help, but I've found them to have very good traction in all conditions. City slush and packed snow is really no problem. They're a little noisy on the highway though -- kind of like when you pass an 18-wheeler -- but it's rather subtle. I have a roof rack that contributes it's own level of noise though.
I used Innovative Balancing ceramic beads and the balance, tires, etc. are really smooth on the highway -- much smoother than my summer Toyo M/Ts (also a 10-ply in the same size). I'm running 8oz in both the M-55s and M/Ts, but may add another 1-2oz to the M/Ts next summer.
They have a bit of a retro look, so I paired them with some AR Mojave Teflon wheels...
js.