I updated to the latest versions of Yosemite and Safari and I find it a significant step backwards. While arrow key navigation is useful. I am encountering other problems that significantly outweigh the benefits.
The biggest and most annoying problem is that when browsing sites and activating a link and then using the back command (command left bracket) the page to which I return is essentially unreadable. VO reads things like "text" or some other form of incomprehensible information. Sometimes, but not nearly always, turning VO off and back on with cmd-f5 will solve it.
Another problem is that on many pages (like articles on NFB Newsline) the entire story shows up as a single paragraph, so reading through an article and pausing between paragraphs doesn't work.
Also as I type this and try to go back and edit, the letters are sometimes echoed more than once and it is far more work to determine cursor location for editing.
I hope these are all my problems and this wonderful forum has solutions, if not and it's the new applications, my discouragement with Apple is growing. As others have noted on this site, iTunes is far more difficult to navigate and use with VoiceOver and I think the same of Safari.