For me the roll whip is more comfortable because it creates a flat area in the middle of the hammock that supports me better. I can sleep more easily on my side and my stomach with this type of whipping. It took me several tries to get it right
It seems that the roll whip is harder to get adjusted for the correct fit. By varying the number of rolls and the size of the rolls gives me different feels.
I have also found that the roll whip leaves some slack in the sides of the hammock. Side tie outs remove the sag in the sides and gives more room inside the hammock. Since the roll whip was derived from the Hennessy Asym hammock I am almost of the opinion that side tie outs may be necessary to create the proper feel of the hammock.
The "W" whip is much easier to do and still gives you a very comfortable hammock. Some of the members here have tried a roll whip and have found that it's just not for them. My suggestion would be to try both and decide which is the best for you.
“Light thinks it travels faster than anything but it is wrong. No matter how fast light travels, it finds the darkness has always got there first, and is waiting for it."