I actually ran the numbers on time dilation! At 600km/s (0.2%), the effect is surprisingly small. We basically 'save' about 63 seconds a year compared to a stat

I actually ran the numbers on time dilation! At 600km/s (0.2%), the effect is surprisingly small. We basically 'save' about 63 seconds a year compared to a stationary observer relative to the CMB. Not enough to live forever, but enough to be late for a meeting.