Daniel, in response to your question about the durability of the RG-50, I've found it to be pretty reliable and well-made. That is, after that addressed some issues after making it. There is a newer version that's been out for a year which fixes the overheating problems we would run into in 90F+ weather. It's my stumper of choice.
Our Rayco Super Jr. is still going, and I like it. It's just too small for production, really. It fits in small places, though. I still remember hitting the fence with it when I was 15.... it pulled itself off the ground and up the fence until it broke off the half-inch cable and hit the ground with a whimper.
Our monster Vermeer doesn't get much use these days. All the drawbacks listed above - have to move the truck to get to the next stump, have to be able to drive to the stump, have to have a lot of big stumps to pay for itself. Just not worth it when you don't have redwoods sprouting all over.
Nickrosis