V-Rail & Belts - What's your experience over time?

Those of you that have had your builds a while and put some hours on them, what can you tell me about your experience with the V-Rail and Belt system over time? Out on the web there's some criticism on the combination, that belts stretch and v-rail can get covered in cuttings/debris that keep the rollers from rolling smooth.

So, I'm curious, those of you with CNC routers, how is the belt and wheel system holding up? Does the rolling surface get debris when cutting? Are you belts stretching, are you getting play in your axis?

I really like the OX design for my upcoming Plasma CNC project. Fortunately for Plasma, the machine will have significantly less lateral load on the Z-Axis (like a router does). However, I want to be able to fit a router to this build as well, and want to make sure this system has the lateral stability needed for it.

When you search the web, and come across questions like this, you tend to get a lot of comments from people who think they know how it would be, but don't actually have any experience with it. I'm really looking for comments from existing builds with lots of hours of use on them. Let me know your experience! Thanks!