Well, my Mozilla experiment is at an end.  I have been faithfully using Mozilla 1.2 as my everyday browser for two weeks.  In the end I like many things about it, but I'm switching back to IE.  Here's why:

• My laptop's trackpad scroll feature doesn't work with Mozilla.  I am so used to drawing my finder down the right edge of my trackpad to scroll, and it just doesn't work with Mozilla.  Which is weird, because the wheel on my desktop mouse works fine.
• The back button doesn't always work.  Sometimes you click back, and you say "uh, how did I get here?"
• No Google toolbar.  Wow, did I miss that!
• Mozilla opens windows under my taskbar.  I have my taskbar at the top of my screen  (yeah, weird, I know, but try it and see if you don't like it, too) and Mozilla doesn't handle this right.  Crummy.
• IE is faster.  It really is.  Day in, day out, page in, page out, IE is noticeably faster.  Especially when you load, like, ten pages at once.  Who would do this?  I do, all the time.
• There are sites which don't work right with Mozilla.  It is really close, but everyone tests with IE, and not everyone tests with Mozilla.  Complicated CSS, non-standard JavaScript, and interfaces to media players can trip it up.
• Mozilla won't use Outlook to send email, it only works with Mozilla's email client.  Independent of my opinion of Mozilla email - which is very low, it looks like Netscape from four years ago - I wasn't trying to switch email clients.  They should optionally use Windows' default client setting, like Opera does.

The stuff I'll miss most:

• Pop-up window blocking.  I forgot how much I hate them.  Mozilla kills them all.
• Ad blocking.  I forgot how much I hate them.  Mozilla doesn't kill them all, but it does a nice job.
• Mozilla can save images as JPGs, IE can't.  I still launch Mozilla when there's a picture I want to save.