How's your Mavericks experience?
I think the most significant benefit of Mavericks over Mountain Lion is how the OS handles multiple displays. It finally makes sense. Well done Apple, catching up to Windows 98 after all these years in this regard.
Overall, I haven't noticed any speed gain or loss with Mavericks. However, memory management in Mavericks is plain awful. I can no longer run some custom scripts with the same exact data and parameters that I was able to run in Mountain Lion. Instead, Mavericks first greets me with a popup window, telling me that my memory is running low. Then a few seconds later the computer freezes entirely and has to be force rebooted. This is not cool, and forced me to roll my work computer back to Mountain Lion.
And then there's wifi. With Mavericks, my home computer can no longer connect to my wifi at home when resuming from sleep, and the only workaround is to turn wifi off and then back on. As you can imagine, this is incredibly frustrating. I did not have this issue even once in Mountain Lion.
So, overall my experience with Mavericks is rather negative. I think this update was rushed, and that Mavericks is still very much beta level software. I find it rather odd that this is happening. How hard can it be to support just a few models and not break them with software updates? In this regard, from what I can tell, Microsoft did even worse with their recent RT update, I mean, they only had one or two models that they needed to support.
As to other new stuff in Mavericks. I think my battery life might have improved somewhat, but this might be due to me giving Safari another chance. I still think that FireFox is way better than Safari, but the increase in battery life when using Safari over FireFox is too significant to ignore. Tabs in Finder seems like a good idea, but so far I have not managed to force myself to use them and have instead continued working as before.