I installed the final beta of El Capitan last week and it all seems to be working well with my various apps tested so far. For those used to Yosemite it will feel very similar indeed and the only real difference I can see is an overall speed bump.
In regard to RW6 it seems a little slower opening now but I have yet to upload any updates since installing El Capitan. Are there any known bugs or issues we should be aware of? My site was launched last week and receiving a lot of traffic now, so I can’t afford any major glitches. I’m using RW 6.3.4, Stacks 3 and the latest version of Foundation.