I must admit, it is the old speed versus reliability thing.
I have noticed (well I can't help noticing) that every so long my X axis sticks. It must be a tight point on the bed. It doesn't happen at all often, so you are tempted to up the speed on the rapids - and everything goes fine, until, one day, it sticks !

and you've ****** another piece of work.
Yes - I can get up to 40 inches per min on rapids - but I have to use 24 to guarantee no foul ups!

My latest thing is machining copper clad for electronic circuits - and the tolerances there are quite tight - so it is even more important.
What I really want to do, is set the machine going, leave the room, have a cup of coffee, or lunch or whatever, and come back and find it finished. I am not at that stage yet !!