Yosemite and Adobe CS6 compatibility

As a graphic designer and Apple computer user since a very long time I was always more than satisfied by everything Apple did with Mac OS X which I can say without hesitation is the best operating system ever released. Unfortunately for the very first time of my life I have to say that I'm very disapointed by the new OS Apple launched last October: Yosemite. I absolutely have nothing against the fact Apple wants to link OS X with iOS and I really love the new GUI of the system. However as a professional I deeply regret having upgraded my system.

I own an iMac 27 inches i7 mid 2010 and a MacBook Air i7 mid 2011 and have updated OS X on both computers by doing a clean install (saved data on an external drive, erased the hard drive partition then installed Yosemite).

Despite the fact that the os is a little bit buggy and slow (I'm not talking about the boot but the finder) I also realized that Adobe CS6 isn't running as good as it did with Mavericks and the previous operating systems. For example, everytime I drag my canvas in Photoshop or Illustrator there's a kind of a 'lag'. It seems like I'm out of ram (I have 12Go on my iMac). It is also impossible to launch Acrobat X Pro. The software launches then automatically quit to ask me to validate the license agreement. Then relaunches and repeat this operation in loop. I precise that I have a legal Adobe license and that the software is up to date. These issues occur both on my iMac and my MacBook Air, both running a clean install of Yosemite. I also checked with my roommate who owned a MacBook Pro Retina mid 2013 with Yosemite, same issue with Photoshop CC for the canvas dragging.

Totally desperate I wanted to go back to Mavericks. Unfortunately I'm not using Time Machine to launch a backup and there's no way to download Mavericks anymore on the Mac app store. My only option was to buy a CD of Mountain Lion on apple.com and have no other choice but to wait a few days for the mail delivery. Yes that's right, mail delivery because even if you buy the software on the website there's no option to download it. You have to pay (even if I already had it in the past) AND wait to DOWNGRADE!!! Incredible!!!

I never encountered any issue with any new Mac OS X version in the past. Years after years I have the sad feeling that Apple cares more about iOS integrity and casual users than professionals. It is sad because OS X is usually very stable and just perfect for design (and other fields too). I really don't want to switch to Windows to use Adobe software properly. Honestly I don't care if Safari is much better than before (it was already good in Mavericks) or the fact that you can continue writing a message you started on your iPhone. A computer is also (and mainly) a working tool and as to be efficient for these tasks. What's the purpose of launching a new OS if its performances for work are worse than its predecessor? And the fact that Apple doesn't allow unsatisfied customers to downgrade is a real mistake. I regret to say that in this particular case downgrading is in fact upgrading, correct me if I'm wrong.

I know there's nothing I can do and I do believe that Yosemite is promising (in the future). But for now it looks more like a beta version and the fact that it's impossible to downgrade by simply downloading Mavericks from the app store is unacceptable...