Few days, ago I bought my first MacBook Pro (late 2013) with preinstalled Mavericks. It worked really great until I updated to Yosemite. Now everything is slow and – more importantly – some tools required for my job are not working.
I must downgrade to Mavericks.
Unfortunately it is not that easy: I can't download Mavericks from the App Store because of Yosemite being installed currently. And I've tried to get 'clean' files from torrents (Mavericks 10.9.1 and 10.9) but after creating a bootable USB stick (with DiskMaker X 4b4) I see a big "circle slash" and installation doesn't start.