Sorry to resurrect this thread, but since this info can be hard to come by, I wanted to add my experience. I have a 2015 Bobcat T770 that I use with a Fecon mulching head. It's used mostly on my ranch for fire mitigation of gambel oak on terrain typical of the Colorado front range, i.e., steep, loose, and rocky. It detracked completely on me once and I caught it in time a handful of times thereafter. I would religiously check track tension at every fueling and I found the factory c-block tracks would stretch or move around significantly. As you folks know, wrestling a 600-pound track on a steep slope is no party.
I found that the OEM tracks really limited my combination's performance on the ground I was working on and it seemed like the tracks kept changing tension. I don't know if it's something about the design of them or temperature variations or what. I ended up switching to the Prowler EXP tracks. I have not detracked in the 600-odd hours since and I also never needed to reset my track tension after the initial install. I haven't gotten the machine stuck since changing them over but that could be because I'm smarter or more careful. I do know they have better ground engagement. It's a pretty small data set, but wanted to share what I had. My tracks are pretty beat now and will probably be replaced again this summer. Short life of the tracks is just part of the cost of working this kind of ground. My biggest complaint with the T770 is that its oil cooling system is borderline for heavy mulching and that it will beat the hell out of you on rough ground. I bought the 770 over the 870 because working on the slopes, especially mulching, it's all about power to weight and the 870 is bigger and heavier without the corresponding increase in power. Anyway, I've been looking at reviews/info for the ASV RT-120 Forestry which is how I arrived here. Back to lurking.