Picked up Freud's SD508 at Rockler's last sale. Did a quick modify on one of the medium sleds. A quick 5-cut setup and she's hummin'. The sled is not necessary for regular dado work but I'll be doing some uprights for some G&G type fat box joints for a gift project and wanted something to clamp to.
As a heads up, there has been a thread or two regarding the ID'ing of the shims. I took mine out and, after determining which size each one was, I used a sharpie and marked them. No more checking or hoping.
BTW, My set came with four (4) .004 shims, instead of the listed two. They were stuck together in pairs so I thought that they were .008's and that I had no .004's. Anyway, you might just want to check that your shims don't stick together.