Can't answer your question but can add my own! I'm also thinking about a ASVI RC-30 or Bobcat tracked loader (T190) as an alternative to a compact tractor. The RC-30 is a small, light-duty machine, whereas the Bobcat can lift 1900 lbs. There doesn't seem to be anything in between in size as far as I can tell. Advantages of a rubber tracked loader over a compact tractor seem to be many, especially if one has wet land which must be worked:
1) Easy hookup and visibility of front mounted implements, including tillers, blades, snowblowers, backhoes and just about anything you can put on a tractor (plus Bobcat has a digger attachment that would take the place of a backhoe for some uses)
2) Can mow or dig in wet areas without getting stuck because of only 2.5-5.0 psi on tracks
One big disadvantage is price, although I'm not sure the difference is that great after considering all the hydraulic add-ons that tractor owners find they need. I think the Bobcat T190 lists at about $33,900, the RC-30 for $20,000.
I THINK that the newer rubber tracked loaders have fewer maintenance issues than the older metal tracked machines, at least that's what ASVI claims.
Sure would appreciate some input from anyone with experience, but these units are so new that there probably is very little real world experience out there. Our local county road crews use the big Posi-tracks. My neighbor, who recently retired from the county, said he wasn't aware of any serious reliability concerns.