Keynote is probably the best presentation software available on any platform, in my experience.
Pages is the word processor and page layout tool. It's just OK for light word processing but pretty good at page layout.
I haven't used Numbers much, but apparently it doesn't provide the advanced functionality offered by Excel. But I certainly prefer it to the Google's web-based spreadsheet tool.
http://en.wikipedia.org/wiki/Keynote_(presentation_software)...
And, FWIW, I only occasionally need a spreadsheet at home and Numbers works perfectly for my limited requirements.
In Numbers' case, I was going by claims I've heard from Excel power users, who say it lacks Excel's advanced functionality. I edited my original post to reflect this.
Mail was Steve Jobs' baby ever since NeXT, and it was built to be used (and useful) internally at NeXT/Apple. It's the best mail client I've ever used, in a sea of extremely poor mail clients.
I have had better luck with Sparrow, but even that has its bouts (its slows down all of a sudden and then comes back, which makes me suspect its doing some background compaction/garbage collection).
Even though I am no longer a huge fan of the Gmail web interface, it still works the fastest.
Perhaps it's related to either your specific hardware, gmail, or Mail's support for gmail?
I love iWork! Keynote is a masterpiece!
Then I might as well use the best tool available to me, and that's Keynote, hands down.
If one collaborates to produce a presentation across suites, you should focus on content and use the common denominator, which works perfectly fine. If it's distribution problems, well, sharing a presentation is always lacking. Slides by themselves miss most of the content. Anyway, Keynote has an interesting export system which creates an MPEG 4 video with chapters and stop points. That's the only way to produce a result with 100% accuracy (unless you design your slides in HTML5).
Isn't that obvious?
I don't think that's an unreasonable expectation.
OpenOffice/LibreOffice <--> MS office is pretty painless. iWork, not so.