I bought one of Garret's HDDs because my Z1 had frozen and the update disc from Pioneer didn't do squat. Garret's HDD was easy to install. The GPS still didn't work for me, but for a different reason. Still, Garret answered all my e-mails and gave me suggestions until I figured out the problem. I felt bad bugging him, but he gave me a great product and great service, above and beyond the call of duty.
P.S. My second problem was that, once I switched HDDs, I wasn't getting any Sirius/XM signal and my GPS was trapped in Los Angeles, like many people have experienced. Turns out the antenna was bad and had to be replaced. It had been on the top of my truck since I got it, but maybe the Philadelphia weather and the heavy mileage wore it down faster than in nicer climates. Anyway, the replacement is on my dash and works perfectly.