David,
I've owned one of he newer RAS saws from Sears for several years. It was easily knocked out of alignment and was a hassle to realign.
I now own several Dewalt GWIs with the heavy cast iron arm. Stays in alignment, has a 90 degree lock and is a wonderful saw to use. The last one I bought was in perfect alignment and has been going strong for 2 years, no adjustments needed.
Be prepared if you buy one to possibly replace the bearings, align, and build a new table top.
- Rick