I love radial arm saws for their sheer solidness and accuracy. It takes up a bit of time to check and tune when you first get one, but its very worthwhile spending the effort and time. Dewalt have changed very little of the design over the years, one of them was using thinner metal for the stand on some models, hence the cross bracing on the 1751 models table. There is a very good book out there by a guy called Wally Kunkel who was one of the original salesman for Dewalt many years ago and he went by the name of Mr Sawdust. He explains in great detail how to tune them up to perfection and also how to build the perfect flat table which is important if you are wishing to cut joints on them instead of just just crosscutting timber to length. He also tells you how to check one thoroughly if you are going to buy one secondhand as well.
I have just bought another Dewalt RAS a couple ofdays ago and I am still trying to identify it. It has hardly been used and has the eight rollers in the head instead of the usual 4 which makes a big difference to smoothness when using it. I will need to rebuild the table as it has been well used and a sacraficial table wasnt installed but thats quite easily done. The motor and bearings on it are so smooth and quiet its brilliant, and this is one reason I much prefer it over the noisy screaming motors of the sliding miter saw.
There is also an American based RAS forum which, although all the US made saws are different to the European saws, still has a lot of useful info such as modifications and accessories you can make or buy for your RAS.
One interesting bit of info is that the current Dewalt saw cannot be used for ripping. The head cannot be turned around to 90 degrees to allow this. Possibly due to pressure from the H&S Exec, I dont know for sure. I dont rip on mine as I have a good panel saw which has a scorer on it so it doesnt really bother me.
Mike