I've been GTD'ing for several years--successfully, I might add. I have Outlook 2003 and have it configured according to David's step-by-step instructions.
I've been and still am interested in purchasing the Add-In, but I'm concerned it will be either a difficult transition or cause me problems at installation.
Is there anyone out there who had Outlook all set up and then purchased the Add-In that might be willing to share their experience with me? By the way, I'm running Windows XP.