My neighbor has the 120's. They run really hot. From everything I've read, their newer power amps are very reliable.
I bought an 88 about ten years ago. It still has the original tubes, and has been trouble free except for a 7 year old bridge rectifier that Mark sent me N/C. It took me about 10 minutes to replace it. My 66 Magnum has been trouble free.
I've upgrade both of the above this year to a 13 year old 99 magnum, and a new Atlas Magnum (kt120's), driving Zu Omns. This house is a rockin'!