Apart from reports of the motion sensors being off by a few degrees there is another by product problem arising from this inaccuracy.
According to CNET and a few other benchmark sites, the iPhone 5S’ motion sensor being prone to being a few degrees off, means that the GPS is not as accurate as it needs to be.
The issue is currently being dissected by a large number of users who are trying to get to the bottom of the motion sensing malfunction, as some believe that the GPS could lead some users to a very dangerous place if it’s not fixed.