In short - yes Dyneema is good for hammocks; just get some long enough to leave long tails after your knots (this applies for flat webbing or rope) and tie stoppers on the end and really chose your knots well or you will wake up on the ground.
Just wrap the spectra around the tree two or three times, that will spread the load.
Less damage than the monthly storms.
It is seriously strong and packs down a lot smaller than tape.
Thanks for the info.
My question about prusiks was more to do with tensioning tarps than climbing.
We have a a number of Hultafors Outdoor Knives with Firesteels
You can see more details here in this thread OUTDOOR KNIVES
The price is £27 and you can pay via the paypal button below.