Hi everyone.
I recently installed Mavericks DP5 to test it out, and to see how it behaves regarding battery life, my most important concern.
I was using 10.8.4 before, with a lot of updates, from 10.6.3 from my old MBP 15" 2010, to my 6 months old rMBP.
First of all, I created a dual boot installation for Mavericks, on the rMBP. I don't notice much speed increase with my old installation.
There is less lag while using the launcher or Mission Control as there is with 10.8.4 with the Retina, that's for sure. But the apps launch as quick as before, the start up is a bit slower (thus I have lots more soft installed on ML).
I used Google Chrome Canary on ML, because Safari was horrible with lots of lags. I tried the Nighty webkit, but it did not improve much.
I reinstalled Google Chrome Canary on Mavericks, and the experience was the same as on ML, quite nice browsing experience, not much lag, quick, reliable...
But I started using Safari 7 on Mavericks. And now, the surfing experience is really great I think, better than Canary, everything is smooth, I don't have much issue, so it became my main browser on Mavericks.
Let's talk about battery life.
I never complained with my rMBP about battery life with ML, it was always btw 5-7h depending on the load, the backlight intensity.
Always unsung the HD4000 on battery, with GFX Cardstatus.
This is only the 2nd time I am on battery under Mavericks, but for the moment, I notice some improvement with battery life.
This is now 6h30 that I'm on battery.
Continuous use and wifi always on, maybe 10 min of standby time.
30 minutes using windows 8 under Parallels 8
30 min streaming videos with flash on
Safari always on with at least 5 tabs, and up to 12.
iTunes turned on roughly for 3 hours
And iStat Menus indicates still 3h20 remaining.
Screen set between 25 to 60% of backlight.
I usually plug the Mac when the gauge indicates less than 15% remaining, I presume that I'll get something like 8h30 of real battery life, which is quite nice considering the power, the screen...
I'll need to do the same test under ML to compare the true gain in battery life., but Mavericks seems to be well born.