Idk about y'all, but I am REALLY loving the new Safari in Yosemite Beta thus far. Everything is so smooth on my battery, incredibly fast, and overall a great design. My biggest complaint would have to be the default short url but other than that I have no complains. What browsers are you using on Yosemite Beta? I have used Chrome for flash related activities like watching YouTube videos and it just consumes too much battery life. If you haven't, try using Safari for a day and see how that works out for your battery.