In our poll of browsers, FF3 was the clear winner with Opera a distance second.

For me, I am starting to have problems with FF3 taking too much CPU and causing my laptop to overheat, so I recently switched to Opera on my desktop. I already use Opera Mini on my mobile phone.

I am starting to like Opera and am using it more than FF3 because it is faster and does not hog my CPU as much. I like how Opera synchronizes bookmarks between all my devices, including Opera Mini.

If you use both Opera and FF3, what do you think? Is Opera on the rise versus FF3?

I have been using Opera for many years since 6.x and except occasional page rendering issues (normally due to IE-centric coding on many sites), it has been my favourite because it is stable and fast. However, there is no doubt that Mozilla/SeaMonkey/Firefox is strong with a wide range of plugins available (that you previously mentioned).

Opera is still my favourite on Linux, although occasionally keyboard will be locked up probably due to some windowing toolkit issue (i.e. Qt).

Google Chrome also loads fast on my system. Often lighter compared with Opera so I tend to use it more often on Windows these days.

I stopped using Firefox about a year ago and switched to Opera permanently because Firefox started taking up too much CPU on my machine as well...i think it has to do with how it interacts with libc...anyway, I'm sick of FF crashing constantly.

I usually have 20+ tabs open in Opera hehe but it handles memory so efficiently that I never have problems on my 2.6GHz, 768MB RAM Intel machine.

I wish they'd make a Linux version of Google Chrome...I'm dying to try it out...I did try it out once ages ago on my sisters laptop but it's about time a Linux version came out!

So right now, I only use FF for testing sites and in case I need to use Firebug to debug some AJAX calls but other than that, it's all about Opera.

Most of the time when firefox crashes its Flash Player that's doing it, most of the time it's consuming 99% CPU because each open tab has 4 or 5 flash ads, but occasionally when I've got dozens and dozens of tabs open, it can hesitate quite badly. I can live with that.

I don't really trust opera. Its a closed-source monolith that used to be for-purchase, evolved into an captive-audience ad-supported program, then finally dropped the ads to become what it is today, but there's nothing stopping them from an abrupt about-face when they start playing with revenue models again.

True. The ad-block add-on is very handy in situations like this.
But I've found that FF takes up massive amounts of CPU even without a single flash object running in it. It also behaves badly on sites that are AJAX intensive...such as gmail, for example

Agreed. I have seen FF3 scorch the CPU when no flash is running.

Then again, one of the issues with tabbed browsing is that if we are not careful, we can have 20 or more tabs running before you know it, each running something "hot".....

Frankly speaking, after running Opera for a week or so, I have scorched the CPU on my laptop on at least one occasion. So, I am not 100% sure if the problem is isolated to FF3, as I am starting to see a similar condition on Opera (on both Windows XP and Mac OS X)

Yes you are right. However, to most ordinary users, unlike development tools, whether a browser is being open-sourced or closed-sourced is not an important consideration at all. What they are concerned is whether it is convenient for them, and display the sites well. Very few people would actually modify a browser engine, provided the browser has a plugin API for extending browser functionality. Today's browser rendering engine is a piece of complex mess that improper modifications may lead to subtle rendering issues.

Of course, everybody is free to decide otherwise.

If Opera charges again or put the ad banners back, people will again shy away from it and thus lose market share. The market force (and presence of more competing browsers) will likely not let them back on the old route again.

I have experienced Firefox crashes on pages without Flash for unknown reasons. At least on Windows, Opera and Google Chrome, IMO, has been more stable in this regard.

I don't open maybe 20 tabs at a time so I don't experience much performance and resource utilization issue. But one thing I know for certain - a poorly written piece of Javascript (not all AJAX scripts are as evil) will in itself be a performance hog and hence only with one tab open may suffice to cause problems. Just like a loop that is run continuously instead of one triggered on an acceptable interval. In those cases, the author of the page is to blame and not the browser engines.