I agree with everything said. I have a Maxx and a Nomad 12. I use one or the other everyday and have for years. I have sent my machines in at least once a year for basic maintence... They are very well built machines.
MARF has saved me more than once. The other issues sound like coincidences.
If you buy a second hand machine, sending it in to the factory is always a good idea. Just bite the bullet send in the Maxx, get it repaired and move on. It's an awesome machine, you won't regret it once it's all said and done.