I must say i am utterly disappointed with Opera 17, I have been using Opera for about 10 years now, and i work as a senior UI/UX engineer and even though I use all the browsers out there for my development work my primary browser has always been opera.
I also operate on a high resolution screen, where its almost a must to use the scale functionality for icons in Opera to make it comfortable enough to use, also all those great customizations with toolbar items and icons which made my life easier is now completely gone.
I switched back to opera 12.16 after 10 minutes of installing opera 17. I see a lot of improvements , but they are completely useless without earlier features which makes opera the best browser out there.