I have the same issues. I have learned to use MS Outlook without any add-ins. I recommend the book Total Workday Control using MS Outlook by Michael Linenberger. Linenberger bases his concepts on GTD and he shows how to configure MS Outlook in a GTD like system. I differ from Linenberger's system in that I retain the use of Outlook categories as contexts as per GTD.
I have just had to maintain 2 systems all these years, work and personal. I am now a subcontractor, so I actually have 3 systems (work, parent company, personal). I have 3 separate NA and project lists. I keep my whole list of horizons of focus on my personal machine, but I have a branch on each work machine (roles and responsibilities). I just started within the last 2 months carrying 2 blackberries as well (parent company and personal).