I've got the frame for the gantry built and installed. It slides easy with just the slightest push of a finger. Does want to rack a little so I'm glad that I will be driving it with a stepper motor on each side. The track will need to be kept clean otherwise it doesn't roll well. Next time I may turn the "track on it's side so that it doesn't have the large surface area to collect dust and debris.
I was very concerned about my table being straight (parallel down both main rails). Be it luck or skill I ended up with only 3/16" variance in the width of the table from one end to the other. The bearings don't seem to mind this at all. Table is also flat within about 1/16". Very important to me as I won't have THC at least for now.
I've ordered timing belt and gears from ebay to use as my drive. I was going to go with chain and maybe I should have but I decided timing belt would be easier to work with. Turned out to be kind of pricey ($300) as I need so much for this large table. Over 60ft of belt and 6 pulley/gears just for x and y axis' :-)
