I put my hand up - confused minutes and seconds. Never was very good at time-keeping...

What also made me wonder, though, is that when I'm sitting watching the wheels go round on the printer, it doesn't seem that fast and I think Clive is right - acceleration is very important as 3D printed components are generally fiddly little things and the extruder is changing direction a lot. I found the same effect doing some fairly fine engraving with the router - I traded acceleration for speed in the settings and the overall cut time reduced significantly. As far as the OP's question is concerned, I think that that is going to raise some interesting design trade-offs with regards to things like pitch of leadscrew/ballscrew.