The other thing that really effects printing time - particularly with smaller models.
Is the speed you print the first layer at.

If you've got a really sticky bed - you can up the speed of the first layer. On smaller prints the first layer can be 50% of the total print time.

I think the fastest I've put down a - succesful - first later is oribabkly around 40mm/s.
Ordinarily i print first laters at anywhere from 5mm/s to around 20.
Just depends on the material, printer and print surface.

But optimising your adhesion and z-gap to enable a faster first layer - can really put a dent in average print times.