I've been using the Opera Web browser as my main navigator for well over a decade. Ever since I first tried it, it felt radically different in speed and general usability compared to the sluggish, feature-poor browsers available at the time. It had tabs and various little things long before Firefox and the rest copied it.
At that time, it cost money to register. It did have a free version, but it forced you to stare at a banner. Even so, I felt that it was superior to the others in enough ways to continue using it.
For years, every single minor release felt like a little Christmas in the same way that any software you use heavily and really like gets you excited about any improvements. Because this was really the case back then: each update actually made it better. Just as it should be.
At some point, I guess they got sick of having such an extremely small market share and changed their business model. They started giving their product away and financed it not with direct banners shown as part of the user interface but instead through special deals with various search engines, essentially adding a little "referrer" parameter to any search query you made through the special search field, which would give Opera a share of the ad profits later.
This (perceived) change in mindset from producing a solid, high-quality product toward making something attractive and shiny and ever "new" to the drooling masses is what pushed Opera into transforming their product into something far worse than it would and should have been today. I'm not saying that it's actually worse at rendering pages or noticably slower now than before, or that there haven't been any welcome additions and improvements in the last years; it's just gradually been made more and more obnoxious in a very disturbing manner. (Simply running an old version of Opera or any other Internet-facing software would be completely insane for several good reasons, security and compatibility being two of them.)
One by one, they added superficial, unnecessary, pointless "features" such as "widgets", the crappy BitTorrent client, or "Opera Unite", while neglecting sensible things such as actually updating the IRC client or generally polishing the interface and deciding on some things once and for all. They keep changing the user interface around randomly and adding really stupid crap like the "Google this" cancer in the context menu, replacing the "Copy text" item, causing me to make about 500 searches by mistake before muscle memory kicked in and taught my hand to not pick the first item.
As of late, not even the "find on page" feature works correctly (randomly). This is of course extremely serious and annoying. It truly makes you wonder what's going when something like that is broken.
Honestly, for the last few years, I've dreaded each update of Opera rather than looking forward to them. Each little change seems to do its best to hammer another nail into the coffin. Just as a small example, guess what the main features of version 11.60 (last stable at the time of writing) were?
I'm sad that they eventually went down the "extensions" route, inspired by Firefox; I was always happy that they provided me with the useful things built-in, in a non-bloated, efficient manner, rather than forcing me to trust some random nobody who has made a third-party add-on.
I almost get the feeling that Opera has outsourced most or all of the development of their product to some $1/hour Indian sweatshop. It's like they have completely forgotten what used to make them unique and great. Opera, I don't want you to look like every other piece of shit out there. I picked you because you were unique, fast and had useful features not found anywhere else.
While I might continue using it until it becomes completely unusable, it is no longer possible for me to recommend it to others as I used to. The amount of fine-tuning (changing insane defaults and whatnot) and removing stupid junk from a default installation of Opera today is way too much trouble to be worth it.
It's almost as if it gives some of the authors of great things some kind of perverse satisfaction to completely destroy their work once it's gained fans. This is probably not the case, but I seriously wonder sometimes.
Small update (?): Version 11.61 at least fixed the mail fetching bug. Before it was released, I tried installing a vanilla 11.60 on a fresh machine just to make sure it was not some "upgrade issue"; the glitch remained.
Small update (?): Version 12 has been released. This silently puts back the privacy-raping keylogger ("search suggestions") even if you have previously removed it. As if that's not insulting enough, they have the atrocity to mention the following in the news post: "Nothing is sexier (to us, anyway) than knowing your personal information is safe and secure."