OK, first, a little background. I have been toying with browsers, as have many of the users here, for many years. I owned a license to the Opera web browser back when it was payware and back before tabbed browsing existed outside of opera/netcaptor.
For some time, I have been dying to make opera my primary web browser. It works well, it has a lot of customizability (for certain aspects), and even recently has garnered extension support and supports roboform/lastpass.
With that said, I have been unable to switch for a number of reasons. First, and foremost, is the lack of usability in the extension system. Extensions are there, and this is a good thing, but I feel that it was done in a very poor manner. Most of the extensions ported to opera lack the full functionality in competing browsers.
Auto-complete is an area that I have always felt opera has been lacking in. Yes, you have the ability to use the notes fields for auto-complete, but that is not a substitute for real auto-complete which remembers text typed into fields with various labels. There are times where auto-complete has saved me a lot of time to find some piece of off the wall information I filled in some time ago, like an old account number I thought I would never need again.
Website support is an issue that is two-hatted. Yes, there are some sites which outright block opera, and then there are some which render differently in opera. However, as an end user, where does the fix action lie? Yes, it would be nice if every developer coded to standards, but alas, I doubt we will see this happen any time soon. New standards are released quite often and to keep abreast of them takes time. That said, I feel that if other browsers can render content in a manner which allows websites to function, why shouldn't opera? As an end-user, I should not have to worry about whether or not the website is to blame or the browser is. It should, to take a phrase from Apple, "Just work".
All that said, I feel that opera has a lot of strengths. It is very quick and offers a lot of good functionality, all packaged into a single executable. But, alas, it is the browser that has remained one I have been dying to love, but simply can't due to many nagging little issues (on top of what I listed above, those are just the key ones which crop up very often).
I would be interested to hear everyone's opinions on this piece of software. Thoughts? Comments? Concerns? Existential Quandaries?