Accuracy of altitude on IFE maps?
Something I've always wondered about is the accuracy of the altitude readout on flight maps on IFE systems. During cruise, it's always a nice, round number, like 35,000 feet. I know that ATC assigns altitudes in round numbers, but it seems to me like maintaining exactly 35,000 feet is like threading a giant thread through a tiny needle but I've never seen 34,999 or 35,001 on the IFE. Do the IFE systems display what's programmed into auto pilot (instead of actual altitude that may fluctuate a foot or two) or are planes just that good at maintaining a programmed altitude exactly, not an inch more or less?