You're making the mistake that many Apple apologists do... assuming that the people who said one thing are the same people who later say the opposite. That's simply not true.
So if we're all Apple apologists, then what are you, a Windows apologist? I simply tell it like I experience it. I have no love for Apple as a company. I think they're largely corporate scum just like Microsoft in many respects, namely greed and overly controlling. I like OSX overall better than Windows for a number of reasons including no registry, no viruses, very little malware and no god-awful Windows8 interface. I've never cared for Linux, especially the horrible packaging system that is all over the place across every version known to man that makes easy software upgrading a chore if anyone stops updating the repositories, etc. I'll take OSX over that crap any day, even with a few odd quirks from time-to-time.
Let's face it. Some people are having issues and some are not having any at all. I see people saying this is the "worst" upgrade in the history of Apple, but I wonder what they're smoking. Yes, I've seen a few glitches, but Tiger and Leopard both gave me plenty of kernel crashes. I haven't seen a
single one on Mavericks (or Mountain Lion for that matter). My only real complaint is that they don't put a second dock on the second screen like the menu bar. And multiple monitors are now SOOOOOO much better than before. By comparison, I noticed very little in the way of improvements between Snow Leopard and Mountain Lion on my Macbook Pro (that doesn't support newer Lion/ML features like Airplay and Airdrop, which are cool on my Mini). But even my old MBP now has better multiple monitor support.
The problem with all these "Mavericks sucks" posts is that most of them are very generic and don't explain "why" it sucks as if they just automatically assume it sucks for everyone when it clearly does not. Not even close. I especially wonder about those that jump on here two minutes after upgrade and start whining that the system feels slower when it's been posted dozens of times that Mavericks does a good 20-60+ minutes of optimizing and spotlight re-indexing when it's first installed (Leopard did something very similar on my PPC machine when upgrading from Tiger) but when it's done, it goes back to normal. Mavericks doesn't feel faster or slower here on my 2008 machine or my 2012 machine. It feels "about the same". I don't love it. I don't hate it. Mountain Lion 10.8.3 and 10.8.5 were both mega-stable (10.8.4 was fracked up bad and ruined a lot of hard drives with its sleep bug). But Snow Leopard sucked when it was first released. I don't think it was stable until at least 10.6.3. Here we are on 10.9.0 and people expect perfection. Well, don't upgrade on V1.0 if you want perfection. Wait until the reports are all saying it's stable.
I tried it out because I had Mountain Lion backed up on a bootable external with CCC. I can go back at any time if I want. But the lure of better multiple monitor support and full screen behavior was something I had to try and it's been good enough that I don't want to go back to Mountain Lion even with a few quirks. Others should decide for themselves, but trashing V1.0 without giving Apple time to address the issues is pointless, IMO.
Apple has (had?) a reputation for producing quality OS upgrades. Having gone from Snow Leopard -> Lion -> Mountain Lion -> Mavericks (on different MBPs) it is pretty obvious to me that there is a slow but steady decline in the quality of OSX.
Oh bologna. Snow Leopard was OK, but it wasn't much better than the final version of Leopard, really and Leopard was a mixed bag (and had a lot of issues at first too), being noticeably slower than Tiger, but having some nice new features like Quicklook and Spaces added. I remember seeing a lot of people saying Lion sucked at first, but I think even it was OK by the end of its cycle. Some of us weren't ready to give up Rosetta at that point, though. Mountain Lion was the best version of OSX ever made, IMO (other than not having Rosetta as an option for a few older software packages) and Mavericks doesn't feel all that different to me other than MASSIVELY BETTER multiple monitor support (if you don't use multiple monitors, I guess you wouldn't notice or care). It also finally has OpenGL 4.0 (big improvement over 3.x).
I'm hoping that Apple can do a massive cleanup of Mavericks on the next update.
Despite following these threads for some time, I don't know what "massive" cleanups it needs. It's perfectly stable here. I see more whining about the brighter side-dock bar than anything else (purely cosmetic). I see some generic claims about slower performance, most made within minutes of booting Mavericks, especially for the first time. What's massively broken?
More than anything, this idea that Apple always has great upgrades with no issues is a
myth. Having been here since Tiger, I've witnessed all kinds of issues with some upgrades. It's typically why you wait and read the reports of people that don't mind being guinea pigs before upgrading. It's why you back up before upgrading. Software support for Mountain Lion hasn't dried up or anything yet, for goodness sake.