Ken, I've got a big capacity fence (52", I think) and the rails seem to be more in my way than anything else. Not to mention it's awkward to cut sheet goods without help.
I bought a set of
these when they had a great sale price on three lengths together as a kit, and I only use THEM now when cutting sheet goods. Put a decent fine-tooth blade in a circular saw and the results are actually very good.
The only thing I don't like is that I have to spend some extra time setting it up to make absolutely sure it's set up square.