I still think the ring buckle system works the best. The best description and pictures I've seen is:
To me, one of the biggest advantages of the ring buckle system is the continuous straps from the rings connected to the hammock to the tree and how easy it is to adjust. You never have to worry if your tree saver straps are big enough, because most of the suspension is made from strapping. If you include a couple of good biners, the setup is much faster than using a small loop in the strap you thread the strap through at the tree side. It's a little bit heavier than the whoopee suspension, but faster and easier to set up. I've seen a few other threads here where people using the whoopee suspension have given up on it due to the complexity of getting them just right.
As to which is better, bare straps, or rope threaded through tube type straps, don't know. I think the ring buckle system won't work too well with the tube type straps with rope inside due to the fact you need flat straps to thread through the ring (or cinch buckles, tri-glides, etc.) buckles. One nice feature of the continuous straps is the ability to wrap the straps around trees several times when the tree is small enough to do so, but to only use one wrap if the tree is too large to make two wraps.