I need a pillow to put under my knees or between my knees depending on if I am on my side or my back. I can't do the side position well in the Clark I cramp in my hip from the bend it puts in me like that, but I do quite well in the 1/2-side, 1/2-back position between those two. Hard to explain properly but pretty comfy. I can usually sleep pretty well on my back too if I use my spare clothes in a stuff sack as a pillow under my knees.
I also do better with the Exped mats under me. I can't sleep well in the bare fabric so underquilts will not work for me. I plan to give the Warbonnett a try next season. It's tough because I love the features on the Clark but it is not recognized as the most comfortable hammock out there.