I think both Firefox and IE do an adequate job of blocking popups. I will use either depending on what I want to do. Because here's the deal as far as I'm concerned: Firefox's beauty lies not in what it does, but in what it doesn't do by default. Finally, I can have an El-Strippo browser without the features that slows IE down. When I want information fast, I use Firefox. When I want bells and whistles, I use IE. Fully loaded, Firefox isn't any faster than IE. It's not necessarily slower, either -- I don't count Firefox's slow load-time against it because that browser's code isn't baked-in and preloaded into the OS like IE is.
Alas, these things alway degrade into Microsoft vs. Linux rock-throwing parties. Some pretend there's room for both, but most of those folks eventually out themselves as anti one or the other. The fact of the matter is that both DO have a place.
I work in a place that has every OS imaginable. From Windows 4.x and 5.x to Solaris, HP-UX, RH 7.3, RHAS 2.1 and 3.0, Z/OS...the list goes on. The point is, that as an engineer for the Windows platform, I've got more instances of Linux running than my cohorts in the UNIX world do. I use Linux for file services. I use Linux for IM. I use Linux to run ESX server (allowing me to run even more Windows and Linux). OS is like any other tool. You reach in and pick out the one you need to do the job the best. It doesn't matter that right now Red Hat is a more expensive tool to implement than Windows. It doesn't matter that I'm just as sick of installing OpenSSL and Apache patches as I am of installing Windows patches.
So more power to you running SuSE and XP. Personally, I only run Linux for server applications because I don't think it's ready for the desktop. I've got an RH 9 box at home and I don't like the UI of either Gnome or KDE. I especially don't like having to switch between the two depending on what I want to do. For example, I love MMS for playing media. Unfortunately, it runs well under Gnome but wrecks X in KDE.
Bottom line is, I think this sort of competition is good. It makes both OSes better. Even the Microsoft guys that I interact with think so (off the record, of course).
I still say the fastest browser is Opera. I sometimes use it's built in e-mail client, you can add a plug in for spell-checking, you have advanced mouse clicks, its something that just keeps improving over time, much faster than IE. But I will say, I do like Firefox, its missing just a few of the feautres of Opera, but does a little better job handling some websites.