There have been some desktop speed comparisons of Opera vs Mozilla, and opera came out significantly ahead. Granted, it will be different on this platform than on a PC, but I believe the comparison generally is similar. Opera has a few more rendering problems, but is faster.

I prefer Opera myself, but I think both browsers should be available, and could be improved. The small memory footprint and fast response just makes browsing more enjoyable.

Now, if only we could have IE7... *ducks*