There is also the Excalibur which I used to have on my PM 66. It worked well, but overall, I found I didn't like using it. It ended up being a pain when you tried to rip and do narrow strips (less than 1"). I did try to use it, I just wasn't as consistent as I would have liked or should have been. The nice thing about the excalibur is it has a 4" hook up for your dust collector and that it can swing out of the way very easily. Still, it is a bit bulky, but it does work well for the price.
I can't speak first hand to the Brett or the Biesemeyer, but I believe the dust collection hose for both of them is separate so take that into consideration.
As for a Felder, I have one of those, and I need to get the dust collection hooked up to the guard. On my Felder, the guard attaches to the riving knife which doesn't work too well when you want to do blind cuts. I did order a true riving knife to go with it for these instances, but I haven't put the guard back on as of yet, but I should.
To me, the "perfect" guard would be narrow (say 3"), be balanced very well, easily removed off the saw, and easily to swing out of the way say when you are wanting to use a tenoning jig, and finally, attach from the ceiling.
