The one thing I'm not a fan of is the horrible, and absolutely terrible animation to take windows fullscreen. It takes a proper 2 seconds for a window to go full screen. I just can't see the reason behind this. At least provide an option to disable this animation or provide a terminal command to speed it up like the mission control animations.
Handoff is one feature I use more than I thought I would. It still feels like a novelty but I'm glad it's there. I use it most to continue my emails on my Mac from the iPhone.
Airdrop on both iOS and the Mac is simply amazing. Now I don't have to wait for Photostream to sync between the two devices.
I'm also looking forward to Siracusa's multi-page review about Yosemite. He hasn't been a fan of transparency, so it will be interesting to hear his thoughts on it. I'm not a fan of it either but I like the transparency used in Yosemite. It's not as distracting and the dark theme really helps with that.
Besides, most sites that have content that lends itself to fullscreen mode (e.g. YouTube) allow you to enter fullscreen mode through the site, so being able to enter through the browser window is not typically necessary.
At work, I use multiple displays, and it's really not seamless when you have one display in fullscreen mode and another not. Imagine having three monitors side-by-side, with the middle in fullscreen mode, and trying to drag a window from Display 1 to Display 3. Maybe this is fixed by now, but in beta, Yosemite sometimes let the fullscreen mode "overrule" the window dragging, so you couldn't see it on Display 2. I know, first world problems, but it's jarring nonetheless.
What's especially frustrating is that there doesn't seem to be a built-in "maximize" function anywhere! The closest I've come to in Chrome is Window > Zoom, but there's not even a keyboard shortcut for that.
The other major issue is that fullscreen actually renders my second monitor completely useless. It just fills up with grey. Why would anyone want that to happen? If I didn't want a second monitor I could turn it off.
I've come to have a subconscious association of "full screen button" == "slow painful animation" and essentially avoid this feature just as I avoid touching fire.
Edit: Shooting it at 240fps in video and counting frames confirms 60fps animation.
I still have the impression that the GPU is struggling with the retina display though, I was just using a 4 year old MacBook Air and the display animations were smoother on it than on my rMBP. I do have it scaled up to the max resolution though, I think that makes the performance worse as the scaling is more complex.
"The item you've requested is not currently available in the U.S. store."
I made this during the developer previews because I don't like the default puke green for most of my IM conversations. Hope this helps some people. Source code also available.
What about iTerm and my bash/zsh configs?
Many more were previously broken but have been fixed given the time that the Developer and Beta-builds of Yosemite have been out.
There were some issues in the beta with large amounts of stuff in /usr/local (I think Apple is building a new /usr tree and copying stuff over very slowly.) I don't know if it was resolved in GM3, but with Mavericks -> GM2, the last "about a minute remaining" took five hours.
For my laptop, I'm going to move /usr/local aside before I do the Mavericks -> Yosemite upgrade and move it back afterwards. (The installer doesn't seem to mess with /opt.)
It took out my java 1.6. Java 1.7 was intact, but I was surprised to find that the info.plist in (my copy of) IntelliJ says it requires Java 1.6.
I had to re-link some perl directories to get git-svn working again, I forget the details.
If you're dual booting, Mavericks will rewrite the spotlight index on your Yosemite volume, if it sees it.
I don't use zsh, iTerm works fine for me.
I can recommend a clean install though. I just did that myself on the beta, and nothing is nicer than knowing that everything works so far (of tools installed).
If you're up for it, I can recommend http://lapwinglabs.com/blog/hacker-guide-to-setting-up-your-....
Also, Apple has been updating Xcode and the command line tools all along, so just getting the latest versions should be all you need to do for developer happiness on Yosemite.
You can check user-sourced app compatibility at http://roaringapps.com
If I had to choose again I would have waited at least until brew updated.
brew list | xargs brew home
As far as features: I've been wishing for the Continuity and Handoff stuff for years. When my computer's running Mavericks it now feels isolated, like a mini version of how it feels to use a computer that's not connected to the Internet. If you're not also invested in iPhones and iPads, that won't be the case, of course.
I'd love to hear what happened at the first FaceTime meeting after the announcement.
Hitting cmd-L will show you the install log which shows you that it is actually still doing something while it sits there for a long time with no apparent change.
$ mkdir ~/local
$ sudo mv /usr/local/* ~/local
$ sudo mv ~/local/* /usr/local
That worked fine for me. Only a few minutes at "Less than a minute" (unlike 2 hours on the previous attempt, before I knew about this problem and so gave up and restored from Time Machine).
I does eventually finish. I'm typing this on my desktop running Yosemite, which took a long long time because of /usr/local, but my laptop is still working on the install. I believe it's been eight hours! (And both have SSD's)
On topic: I have been using Yosemite since the first beta, and it is a nice upgrade. I use a 3 year old MacBook Air, and on a non-retina display everything still looks good. Unlike other commenters, I like the Spotlight changes. I also like the better intro with iOS 8 devices.
Also, my biggest frustration has been the workflow change of the "maximize" button to it's new role as full-screen button. I wish there was at least a config option to switch it back. I'm fine with adding it as an option, but completely breaking the workflow seems unnecessary IMHO. I guess that's why I use "Spectacles" app for window placement keyboard shortcuts.
You use dev tools and stuff like homebrew/macports a lot: fresh install is a lot nicer.
You don't use the above that much: Upgrade is fine.
As for the packages, I had a lot of different packages that were built for Mavericks, and needed updating, and would constantly bump into something new that needed something reinstalled etc. Various reasons for this, like Apple moving around system utilities and upgrading various things.
EDIT: Just to be clear, all is solvable with the upgrade. It's just a bit cleaner with a, well, clean install ;)
By the way, Yosemite runs really well on my MBA. The only thing that bugs me is the hideously ugly folder icons.
Even the new features seemed to be focused on iOS.