Problems I have had, almost ALL my own learning curve:
Installation of software and setup issues slowed me way down at the start. All me there.
partial test prints and failed prints: mostly getting used to Slicer, Pronterface, temps, and bed/extruder levelling.
Other failed prints: windows damned update, power outages during storm.
Printer issues out of the box, shipping had a sensor tripped, and so I knew there could be bits of extra work.
loose set screws in several places, causing little issues and mis prints.
set screw for gear that drives filament loosened, so the filament stopped mid print. adjusted easy.
X axis had come loose during shipping, connected it back easily, tightened set screws, adjusted sensor.
Flickering LEDs for a few minutes once, and Y axis belt piece rises during print, so the bed hits it occasionally, or the belt comes off mid print. Haven't informed customer service of the issue yet.
Another gear started making a minor vibrating, needs a tweak in there somewhere, too.
so far, considering I'm a brand new beginner, it has all been very minor and easy to fix issues. Mostly set screws. As for service, I'm having great service in the start up stages. I don't know how it will be later on, but they have jumped at every chance to help, and often are waiting for me to get back to them. I am not in any extra paid service program, so I don't know how it will be after that. They do have an active forum with other users who can help, too.
Motors are very quiet. I have the dampeners added to mine to make them even quieter. Only because it is in my bedroom office for the first few months. I'm now thinking I may have been just fine without the dampeners, since it will be moving into a separate office once we move.
I am not comfortable leaving it printing overnight, but that is my lack of experience. I am not familiar enough with 3D printers to effectively compare it to other models, but I am very impressed with how strong and sturdy it is, and with the high quality parts in the machine.
I really do wish I had had it for a year already, to give you a much better idea, they are just so new to the market.
RoVa3D with five nozzles (first nozzle down, four to go)
Slic3r and Pronterface
Filastruder and Filawinder - soon enough
Current hurdles - humidity, offsets