^ As DSatz implies in his post, it is probably a pretty rare event ("As long as that noise floor is so low that you can't hear it (always, 100%, money-back guaranteed under all circumstances)" and "If the noise floor is ever audible--if any possible type of signal, or combination of settings and signals, can coax it out of hiding") so a sample of two isn't exactly dispositive (I guess it wouldn't be even if it was fairly common). Hopefully, Zoom's implementation is such that it will rarely, if ever, be an issue.
I am intrigued by this technology, but I will let others be the early adopters. My current recorder has a broad enough dynamic range that I can already set it so it will never clip before my microphones and still capture the whole dynamic range of a show. It requires a little math, but I don't mind that. If the F6 or the MixPre IIs prove to offer a major benefit (beyond saving me the math), I may give one a go at some point...