Nope, never had a problem with them. I have put a carrot in the bottom of the cage just in case extra's get hungry and I do notice the carrot gets munched on. But I have been using them exclusively for a year now without any issues. I will also say I don't free range them in my crested gecko tubs either, but not because I have had issues just as a precaution. I did have a couple escape in one of my adult male cresties bin and lived in there for more than a month before I could find them and get rid of them and didn't have any problems with the gecko

The whole crazy cricket thing is WAY over stated!! I really think that it's one of those things like superworms eating holes in your chameleons. They do bite...but no worse than a superworm. They grow almost twice as big as a brown cricket, and I have never had an issue when they were the size of a brown cricket. The two times I have been bitten was when I was being stupid and with full sized (huge) adults.
I am sure a bunch of places have them but I have always gotten them from Mulberry farms. I think the Bug Guy has them too.