Personally, I do not. Have you ever used the Moto Atrix? The FP Scanner on that phone worked very well IMO, and I'm sure some may disagree about that. That's fine, but a lot of people feel that the Atrix's FP scanner did indeed work well. So that says that whoever built this FP Sensor had the Tech. Knowledge and Ability to offer a dependable, quality, and effective product that was first sold around March 2011. To get to the point, the company that made the FP scanner on the Atrix was Authentec. Yes, this is the company Apple bought a few years back. See where I'm going? We can assume that the FP scanner will be far superior than the one on the Atrix which IMO, was great. We can assume it will be superior because they've had years to further develop the technology, etc etc etc. That's IF the 5s will have a fingerprint scanner, which it probably will. But if it doesn't, I might stick with my 4s (depends). The reason why I didn't buy the iPhone 5 was because of the lack of FP scanner. But the area I live in did recently get LTE, so considering that, as long as I am able to pre order and get the 5s on release day I will most likely upgrade. I'm also hoping there will be a decent case available for the 5s as well when it releases, considering the new FP Scanner will make it so I can't use the cases I normally buy (Lifeproof).