It's simply the best tool for the job, bar none. It's kind of like buying a Mac. Everything just works.
Although it's outdated now, I think the II N is the first upgrade-proof DSLR that hit the market. The updates over the MK II are somewhat subtle, but really are huge when you come down to using the camera all the time....
I have a 30D that's now become my backup, it puts out good images, but it's kind of a bitch to use in certain situations, like you said.
that 70-200 f/4 is a sick lens, I've got the 2.8 version, they're seriously some of the best lenses made for 35mm format cameras.
Basically, if you're making money shooting, 1 series cameras are a good idea. If not, there's nothing wrong with the 5D/30D series cameras, and you'll save a bit of money. (The new 5D II build quality is on par with the 1 series now, which is more than I can say for the original)
I go to school for photography though, and my school-job is renting out all the new cameras from the photo cage, so I can probably talk enough shop about cameras to write a 10 page paper.........