In any case, the resume times for most macs are pretty much instant. You might find that the biggest delay in resume time is the responsiveness of the display, as the computer will usually be ready before the display is
It helps to know the various "types" of sleep available through the pmset command
from this this article
0 - Old style sleep mode, with RAM powered on while sleeping, safe sleep disabled, and super-fast wake.
1 - Hibernation mode, with RAM contents written to disk, system totally shut down while “sleeping,” and slower wake up, due to reading the contents of RAM off the hard drive.
3 - The default mode on machines introduced since about fall 2005. RAM is powered on while sleeping, but RAM contents are also written to disk before sleeping. In the event of total power loss, the system can be boot off the sleep image to resume previous operation
5 - This is the same as mode 1, but it’s for those using secure virtual memory (in System Preferences -> Security).
7 - This is the same as mode 3, but it’s for those using secure virtual memory.
Modes 1 and 3 will have the same speed of resume (they both retain RAM contents during sleep, wake is practically instant), but mode 3 will require a longer time to fall asleep (usually 15-60 seconds). In the case of power failure, mode 3 allows you to boot your laptop, and after about a minute, the RAM contents from before the last sleep would be restored from the sleep image file to RAM. Mode 1 lacks this, so all running applications and unsaved data will be lost in event of a power failure, but sleep time is almost instant