I keep two completely separate GTD systems. I don't want my personal life sitting in my client's systems and I don't take work home as I spend enough of my life doing that. Besides, all the project support material is a shared team resource in the client's secure system.
My Areas of Focus are completely different. For me there is just no overlap, I don't do much go-live data conversion in the house.
At the office, I only check my personal contexts (on my phone) when I'm on a break and my personal calendar beeps me if I'm meant to do something soon. Otherwise, I'm supposed to be working.
Fun is being on top of things - Sir Richard Branson