Interesting design. Looks very servicable and fairly stable. Are the slider hardware a standard (bubble pack) item from the hardware store? They look like the sliders used in the lids of cedar chests and the like....I'm asking because I've looked at that prefab hardware several times and wondered about its application to exactly this purpose.
Once you have had some time with it, please spin us a yarn about it's relative merits and where the design could be improved.