I use Opera for nearly all surfing, including AT. IE is only used every once in a while. Opera is, in my opinion, and according to extensive tests done by a German magazine, faster by far than Netscape and a little faster than IE5. It also aheres very well to the web standards set by the W3C.
I love the fact that I can surf on 10 sites at the same time without running into any problems at all, neither does it use too many resources (running a Duron 800 now, but it was easily possible on a Cel300A, as well), nor does surfing with many windows become confusing. Switching through 10 websites using '1' and '2' takes about the time IE uses to display a single page...
I also cannot see why Opera should be less 'robust' than IE. It doesn't crash often, and *if* it does crash you can always recover your session. A crash is only a minor annoyance, not more.
The Opera download window is indeed very nice. I used GetRight extensively before version 4, but now I don't really need it anymore. Opera keeps track of my downloads and is able to resume. The only things I still use GR for are huge downloads (I'm on ISDN) which I let run over night.