I was looking for info about Yosemite availability (Can't download yet in my country), and I saw that their price dropped and they are updated. I can't give you any resources to this, though. So I'm not sure if it's true.
Uh... I've got 4 GB of RAM in my Macbook Air and I was looking forward to updating it to Yosemite. Everywhere it says "2 GB will run it, but you'd better have 4 GB".
But I think you're talking out of your experience?
Trust me, Apples Minimum is not enough unless you area a casual user. I run out all the time with even Mavericks and 4GB RAm. Fresh install. Nothing wrong with the Mac in any way. Safari and Mail and messages I open Activity Monitor and all RAM is used up.
Many here on the forums have seen the same thing with only 4GB and either Mavericks or Yosemite!
I can't find the page where it said you can use your backups to roll back to Mavericks, but I swear I saw that lol.
Apparently, I would have to erase my disk and then use Mavericks installer to get back to it. Then my Mavericks Time Machine backups would be useful.