I’ve been a loyal user of Opera since version 5. Back then, they were the innovators of features like tabbed browsing, mouse gestures, and excellent support for web standards. I even paid for it back then (as it was on the “shareware” model) since it was just that awesome. I’ve been using it ever since.
Sadly, over the past couple years, the quality has definitely gone down. It may have started roughly around the time Opera got a new CEO, though I’d be hesitant to place the blame completely there. It crashes much more often. It likes taking up CPU for no discernible reason. The next version, Opera 12, will be removing many features that make Opera distinctive, like built-in BitTorrent support and their awesome Opera Unite idea. Opera just doesn’t seem to be the cutting edge innovator that they used to be. (Or perhaps, they’ve been so busy trying to innovate that they lost their core focus on making an awesome browser.)