I have been running the GY-MTR's for about 3 sets, but couldn't get them when I was up for new tires the last time. I finally picked the 35x12.50x15 MT - MTZ"s the last time. They have been a really good tire in the rocks, mud, deep snow, and slickrock. Like most mud tires they really suck on snow pack and ice. I had some problem getting used to the cold tire flat spots in the mornings, 1 or 2 miles. The side walls are stiff compared to MTR's but I came to like that as they are also tuff against rocks. Twenty eight lbs. is just about right for them and they were reasonably quiet when they were new, but like all others, the more you chew them up on the rocks the louder they are. The MT-MTZ"s are lasting longer than the GY-MTR's did for me, but I have too rebalance the MTZ"s more often, but also the rocks are really hard on tires so that is not unusual. I have not run the pro-comps personally, but I have known some that have I have read post's on Colorado4x4.org that have prevented me from considering them. I'll probably buy MT"s the next time.