My OS X Mavericks Rating
I upgraded to Mavericks a couple weeks ago. No sigificant problems with the upgrade, but it took a lot of time or effort.
I'm giving Apple a 4 out of 10 (10 is best) for Mavericks. Unless you must update to this operating system version to fix something like the inability to completely access internet web sites (the problem I was having), or other problems with obsolecscence, then I'd steer clear of it. This is the operating system that tries to do too much, and in doing so, constantly gets in my way. Mouse functionality is just plain bizarre. Something as sensible as the keyboard shortcuts in the old Preview, exist no more, and I can find no settings that restore them. Clicking on a post-as button (posting in a blog) causes a menu to pop up asking me if I want to "look up" my own posting ID. I could go on. These things are more than just annoying. These problems, and there are many, many more like this did not exist before. Mavericks is just plain slow compared to my old OS X version--it seems to try to do too much, but fails to do the necessary simply.
A couple weeks ago, I would have given only a 1 out of 10, based on the assumption that old problems had been cleared up. I've gotten used to the issues I've described (+1), and partially fixed other issues (+1), and Apple gets 1 through charity (they've been great in the past, hardly putting a foot wrong).
My next computer upgrade, if there is one, will proibably involve LINUX, and OpSys I've used before along with UNIX (where life on earth began).
Mac Pro, Mac OS X (10.6.8)