You need swap to properly hibernate, which means save the current state of the system to disk, power off the computer, then resume the previous state.
However you don't need a swap partition/file to suspend the system, the difference here is in this case, the kernel will only turn off non-essential devices of the computer, (everything except, northbridge, MC, RAM, CPUs, probably southbridge too.). In this case, the kernel will attempt to load the current state of the system to main memory, then go to sleep, waiting for an interrupt to wake it up, then proceed from that stored state. this is known as STR (suspend to RAM). which is the default behavior in most systems.
So, swappiness doesn't have an actual effect on how fast or slow your system recovers from hibernation. However, reducing swappiness speeds things up for other operations. What makes things faster is suspend instead of hibernate, cause, as you probably know, RAM access is a lot faster than disk access.
Ultimately, I'd say it depends of your situation, if you're going to power off your computer (battery is depleting), or just leave the computer in power-saving mode while you're not using it (you make a script that can tell if you'd fallen asleep at the keyboard, again xD). etc.