Depends if your company is ready to use Spreadsheets instead of calculators. I find this to be a good analogy w/ my customers. A spreadsheet can make a confusing calculator if all you need is a calculator, but if you know what you're doing, a spreadsheet will make your work a *lot* more efficient. And you can program a calculator UI for a spreadsheet.
Lotus Notes has a much better UI in 8.x (everyone griping about probably has experience w/ Notes 4.x...it's like saying Windows 2.0 sucks when everyone is on XP or KDE or Gnome..seriously :-), built-in Office doc editors, security designed from the ground up (secured databases and network traffic and PKI), *secure* business level IM, etc. Mail/Calendaring just happen to be applications written on top of it, but you get all the built-in plumbing (security, replication, etc.) that are part of Notes.
So you have to ask yourself and your coworkers: do you want a calculator or a spreadsheet? What if your competitors are using spreadsheets and you're stuck on the freebie $5 calculators that Staples gives out? Who do you think is more efficient getting their job done? How much is that $5 calculator really costing you? ;-)
