We use a Robot Coupe 350 Turbo for heavy use, and it gets used and abused. Had to replace it once in four years.
I've used the dynamic machines in the past and they are good machines.
I have purchased a small mixing wand in the past (Waring) just to alleviate some stress on the Robot Coupe, but it got recalled and prep cooks said "it couldn't mix Kool-aid". Never had that problem with a Dynamic machine.
Actually, I've never had a Dynamic machine go down. Had some gears strip on their salad spinners, but I just chalk it up to age of the machine.
Short answer, yes. They rule. Get one. You won't regret it.
Don't know who you would buy it from, but I bet if you went through a reputable supplier, they would stand behind that name.