I have had problems with all three of mine.
The first generation of syncrowave 250s were a lot more problem free.
Miller has to many engineers making to many changes to things.
I have been told that the problems have been worked out of the new ones but that is a lot of money to spend if they arn't going to be problem free.
First generation 250s can be had for $1500-$2000 in good working condition. The last 250dx I bought was about $5,000.00 with 50' leads,regulator,foot pedal,and ground cable and clamp.