I've got three of them and one runs well...while the other two seem to have an electrical problem that I haven't figured out yet. They run well then all of a sudden stop...start...the stop. If I touch the shell very gently, I can get them started again. Whatever the problem is (and it's on my list to do) I'm guessing it's very slight since it doesn't take much to fix it...Overall, they look great, run smoothly and are only slightly louder than a Kato. I'm happy with them - even the ones that don't run without problems - and would buy a few more if needed. And as soon as I figure out what the problem is with the other two units...I'll be running a string of three and enjoying them even more.