I'm just a weekend warrior on my own personal cars and I have to agree w the GG6. I absolutely love it. I have 4 different backing plates and haven't had an issue with any size yet. I, personally, prefer to leave the handle on as I feel I get better control over the machine. The handle on the GG6 was also the selling point for me over the PC. The PC has a stick handle as opposed to the GG6 D handle. Being a noob when I purchased it, I was concerned that I wouldn't be able to control the pressure as easily with the PC. For example, the pressure would cause the pad to work crooked as opposed to flat on the paint.
However, you can see on the forum how popular the PC is so YMMV. This is just my personal experience.
Not sure if this makes any sense but hopefully it helps!