This is only the developer build and it feels more stable than 10.10.4. everything is extremely responsive and feels fantastic to use os x like this again
So you have Radeon 6490M or 6750M GPU? Although it doesn't matter really because both support currently openGL 4.1 and openCL 1.2, which, I believe, are the minimum requirements for Metal.Much improved on my MacBook Pro too. And mine is an old one. Early 2011. No SSD and 4 GB RAM.
Just curious, do you have transparency enabled and default contrast settings?I'm still using my old mid-2012 Retina MacBook Pro (the 2.3GHz model with 16GB or RAM). So far so good, everything feels faster and more responsive than with Yosemite.
And the best part is... I only have one app that doesn't work so far amongst all the apps I use
I remember last year when I installed the first Yosemite Developer Beta: That same computer was barely usable (Slow, crashes, many incompatible apps, connectivity problems, etc.)... El Capitan is clearly a better, more stable product, even in its current beta form
I'll use it as my daily driver without any fear. OS X finally feels as fast as Windows 8.1 on my laptop! I'm happy