I’m probably 1 of the last people here to see something like this, but here it is anyway. This guy tries pushing his printer to the max & gets crazy fast print speeds: [U]Printing at 800 mm/s on a FDM CoreXY - Can the HevORT do it? - YouTube
I prefer printing reliably. If a print needs 5 hours, who cares. If it would print in 1 hour and fail three times I have four times the work and it saved 1 hour.
I rather spend the 5 hours doing something useful AND get a good result. 
Agreed, but I don’t think that’s the point. I think he’s exploring the upper limits of what might be possible. Once he’s found the upper limit of reliable printing speed he can back off 10% to 20% and know he can print reliably, with good quality, and excellent speed. IOW, he can maximize the throughput. Think what it could mean if his printer could reliably print at 500 mm/sec.