I just recently joined the Dutch family with the addition of two Tarp Flyz to my kit. I got them in anticipation of some camping I was hoping to do on the AT near Damascus, but it didn't materialize. But I digress.
I have not used them in the field, but I liked the idea of having the Flyz on both ends of my continuous ridge line made from Zing-It. It seemed to have the most flexibility depending on how far apart the trees are and doing the "V" Dejoha suggests working around the hammock suspension. I use klemheist knots on either end of the tarp at the ridge line so I can slide and center accordingly. I use the black drawcord that DIY Gear Supply sells for those. It really grabs well with just a few wraps. It is expensive at .21 per yard, but that's how I roll.
I keep the ridge line attached to the tarp and use homemade snake skins for storage. I can center the tarp before I even unroll it if I wish that way.