I also own one. Bought it off here, and the motorized knobs were replaced by the original owner. He had it done at a shop in Minnesota if I recall correctly. I have never had an issue with them.
Personally, I don't use them as a true "second channel" switcher, but rather a separate EQ setup for a different bass. I mainly play jazzes, but when I want to break out the Precision, i switch over to channel 2 where i change the mid settings and bring in a little more low end. I have all my effects on the floor and don't need to switch to a hi-gain channel through the amp itself. My muff takes care of that.
I would also agree with the prior post about the comparison with the Mesa M6/M9 Carbines. I had an M6 before the Fusion 550, and I wanted to love it, but it continually had power failures, so it went back to GC, where i had bought it used. Crazy thing was I tried out a new one in store before ordering the one I bought off their used site, and it did the same thing in store. Must have been a bad run of those.
The GK doesn't quite overdrive like those Carbines do, but it has a ton of headroom, and takes pedals very well, which is my personal preference. The GK almost fuzzed out when you crank the gain, which I love. I really like the sound when cranking the gain knob, but it's different than the carbine stuff when it comes to built-in distortion, but that's a personal preference. I prefer the GK.
I also prefer the clean tone. I can barely push mine past 9-10 o'clock, and even more so now that it sits on top of a Mesa Vintage Powerhouse 412. I will repeat that it loves pedals in front. I didn't think I would find a newer amp that would take pedals as well as my '74 Acoustic 370, but this GK really shines with pedals in front. I am a user, and a believer.
If you have any other questions, feel free to post here or PM and I would be more than happy to answer them for you!