I was considering a sliding table attachment for my Unisaw, but after reading about the Festool plunge cut system, I'm thinking about how nice it would be to have the portability. Anybody use this saw and rail system?
It is a top notch tool, but it is not fast or easy to use for repeat cuts. As for portability, it is the best you will find. Cuts are as clean as a $20k beam saw... just not as fast.
For cutting up sheets of plywood, it is faster if you buy a sheet of 1" thick foam insulation board, lay your plywood on top of that, set your blade depth to about 1/8 below the ply and make your cuts. One 4X8 sheet of styrofoam will actually last quite a while before needing to be replaced.
I rarely use the saw now, but carry it on the truck for that occasional cut on-site.
I also found that it paid to rip a reference edge on sheets of ply because the factory edges are often off quite a bit. Since you are measuring both ends of your cut to establish marks to lay the guide on, if the factory edge is off, it shows up with the middle of your cut either being too wide or too narrow. For cross cuts, I use a square to establish my reference line for the guide. I'll check the factory edge. If it's good, I'll us it, but more often than not, it's off.
Initially the rubber strip that serves as the edge of the guide is pretty accurate. Just put it on your marks and cut. It's easy to get within 1/32nd inch or better for accuracy. Relatively rapidly, this accuracy decreases as blade wobble eats into the rubber strip. The end result is you tend to cut your material oversize. With time, I learned just how much I had to cheat the rail to the inside of my marks and I was back within that 1/32nd range again. Alternatively, you can replace the rubber strips more frequently.
Obviously, accurate measuring and marking are critical. A fat carpenter's pencil doesn't cut it. It helps to keep the running surface of the rail and the base of the saw waxed for smooth operation.
As others have pointed out, the Festo saw and rails don't replace a good sliding table in a shop situation for speed and repeatability, but it is definitely way better than a chalk line or wooden guide and circular saw. It doesn't take up much space and it sure beats manhandling full sheets across a table saw. The ability to hook up a Shop Vac to extract sawdust is a great feature. Cost wise, my setup actually cost more than most of the smaller sliding tables like the Excalibur.