Well I've been doing a little more research on the Igus system. I still like the looks of the Drylin T system but having to put one of the sets of shuttles in floating mode doesn't thrill me that much although the load capacity should be enough for my needs but this is just farmer calculations right now.
I was hoping someone has had some experance with the igus system and could offer up some advice. The W square rail looks nice but I don't know how much slop there would be and if by adjusting the shuttles some of the play could be taken out of them. I think I'll call Igus tomorrow morning after I get off work and talk to them about the different systems. I'll keep everyone posted as to my results, may not get much of a reply here but on a search for future reference these posts can be great.