AlexW wrote:
Has anyone used any of these or have any other advice on the subject?

Hi Alex

I have 1 24" one from Silverline Tools which seem identical to the Perform
and is almost exactly the same price. As a basic guide rail it does the job
very well. I use it mainly for routing dados, for cutting with a circular
saw I use a 'sawboard' http://members.aol.com/woodmiser1/sawbd.htm which you
can make yourself.

If you do, glue the guide ripper along the centre of the base & trim both
side to give room for clamps.

Dave