Ok, I can contribute to this
I've been an Office user for many years for work including Visio for a wide range of purposes on PCs.
Zip forward in history and after finishing with the job I was left with two options - mac:Office or iWork'09. So I downloaded the 30 day iWork'09 demo from apple to try iWork. Up to this point I have been using NeoOffice (the mac orientated pre-compiled package of OpenOffice).
First thing that struck me is how unclunky, fast and uncluttered it is compared to NeoOffice.
After the initial - how the hell do I do X as I've been used to MS Office.. I've finally got the hang of Pages, Numbers and KeyNote (PowerPoint). It's features are available in Office and I would say Office has more gadgets but when I thought about how often I used them it became clear that there's lots of features I don't use. Once I'd found the features I did use then I was away - the work flow is easier as it's not attempting to support multiple ways of doing the same thing.
NeoOffice at this point looks like the big lego blocks and is very very slow compared to iWork and MS Office. I've used NeoOffice a lot and I'm not going back!
iWorks can save your files as MS Office and export as PDF etc.
I found iWorks initially frustrating because I didn't know where X was - which I could find in two seconds flat in MS Office due to familiarity.
iWorks is extremely quick. I don't know how fast MS Office on the mac is compared to it but it leaves Office'03 in it's dust. It may still have a little way to go to be as good as MS Office.
Job's next target is the dominance of MS Office - so expect iWork to get better and better. Yes MS are looking to put VB support back in to mac:Office but at the same time it's a curse for MS who want to block Apple but can't as MS are using IPR from Apple in their new versions of windows in exchange for MS creating MS Office on the mac (I read that in a well respected Job's Biography).
I've grown to like iWork'09 a lot (I bought it four days into the trial period). It's quick and very easy once you know how todo things!
There- another opinion (or tired rambling!).