I tried to use Keynote to present last week at an event in Chantilly in France. I faced 3 difficulties and with the help of the A/V team on location to present.
1) I first tried to import my Keynote presentation (designed on my MacBook Pro) on my iPad. You can do that easily by syncing both devices with dropbox. Unfortunately, Keynote on the iPad loses your formatting !!! See the screenshot below.
I had therefore to forego to present with keynote, and use my MacBook Pro. This is also a problem for the future as I can't go anywhere with just my iPad, unless I use very simple fonts and transitions. Nothing fancy.
Too bad, that's $9.99 spent for nothing on the iTunes Store.
2) Running Keynote on my MBP, I tried to use my iPhone to control the presentation. There's a $0.99 app for that. However, although I had both devices connected to the same wifi network, firewall off, had rebooted everything, there was no way to make my MBP see my iPhone. The problem is well documented on the support forums (sample), and it still not solved.
Luckily the A/V team on site had an USB clicker that worked immediately like a charm.
3) finally, I have not bought the adapter to connect the iPad to a VGA projector. That's a $29.00 gadget on the iTunes Store. And I already have the MBP connector both for DVI and VGA. But they're not compatible with the iPad...
Lots of money lost for a document production and presentation process that just doesn't work ...