Just started poking around with this yesterday, right now I use eGroupWare for my contact management along with the calendar and such... and use ProjectPier for a client center for our construction project management.
This has the potential to replace both with an all-in-one solution, but there are a couple "must-haves" I think for me before I could fully move...
1) custom fields in contacts.
I have hundreds of subcontractors in eGroupWare, their categories allow me to split them up according to type of work they do (painters vs plumbers for example). I've figured out I can use Workspaces to basically do the same thing. But, I need custom fields under the contacts for a couple things... we currently rate each sub on a scale of 1 to 5, and I also have a custom field for if they prefer to receive bid invites from me by email, fax, or if they are on our mailing list.
2) data export
along with sending those bid invitations out, I need to be able to export a group of data so I can cut and paste the fax numbers in to my fax software, and do other things like create mail-merge for printing labels (like for upcoming Christmas card mailings).
Other things that would be great...
data import - I have a couple thousand contacts in my current setup, the prospect of retyping all of those.... yuck.
When adding a new user, I need to manually click every workspace to add them to... most of our users will get access to all... a selection all/none would be nice.
Ummm... I think I had others, but can't think of them right now, will post again as they come to me.