All the 660's are still running except for one, got left in a cow barn in crap and corroded itself to death. But for the most part the 660's are solid. The 372 clones that got put into real use ALL had bottom end failures, the ones in hobby use or occasional use survived. But the 660's even survived real production use for a couple of years until the folks got bored and went to new saws...but they didn't die. Could NEVER get the 361's to run right. Trying to rid myself of them. And the big 880 is doing fine, just so big and heavy I can't run it much or my back will blow out I guess interesting enough the opinions I formed back in 2016 2018 haven't changed much. 660's can be made into real saws, 372's good for toys, and I don't know about the rest. Seems like so much is still a moving target. I would stay with 660's should I go back to that frame of mind