Same. It's more efficient then the 24hr production when it comes to time management and it has the same resource output as 24hr.
While this might seem to be true on the surface, if you look a bit deeper it isn't necessarily as true as you might think.
A motivated 24hr will outproduce an unmotivated 8hr, and any supply boosts you have will really add up on the 24hr.
I have found in the past that it was impossible to get the majority of my 8hr productions motivated, but have never had a problem getting my 24hr productions motivated. This is based on the 40-50 production buildings I usually run until my Chateau is high enough so I can start eliminating some.
Also, 24hr productions that let you fulfill the requirements for recurring quests give those rewards in addition. 8hr doesn't have that option.
If you only run a few 8hr productions and don't have any problem getting them 100% motivated, then you are golden.