Update on the one I'm using. Recent issues have been hot back end (3rd unit) and operating issues when clicking it on (2nd unit). The first click it will go red, then off. Second click is blinking red, then off. It does this for about 4 or 5 tries until it will actually go blue and heat up. Then repeat the process for each hit.
The reply I received back was 'sounds like a loose pin, tap the back end a couple times and it should clear it up'. I did that, it didn't work. I kept testing, tapping a couple more times and sure enough, it got back to working like new for about 10-15 consecutive hits. Was really cool.
But now it's back to the issues of it not working right. Still tapping the back end but it's about a 50/50 chance it works correctly right now.
Oh well.