Do you use a trail hammock? If you get the chance (no rush -- I'm planning months ahead), I'd enjoy reading your comments on their utility.
I have used a trail hammock but with mixed results. The model I have is a Hennessy Hammocks UltraLight Backpacker Asym (asymmetric) model. See http://hennessyhammock.com/catalogue.html. Scroll down until you get to the right one. It comes with a rain fly that does not reach the ground.
PROS:
--The world is your campsite. You're not "tethered" to flat spots. Two trees, and you've got a campsite, level spot or no.
--Fairly light. Mine is 1 lbs 15 oz out of the box.
--You can carry less padding (e.g. Thermarest, Ridgerest, or the like) or none at all, saving add'l weight.
--Really comfortable once you're ensconsed inside them. Nothing pokes you in the back when you roll over.
--Ventilates extremely well, excellent in warmer weather.
--Have seen no wear on floor of hammock -- it never touches the ground.
--Absolutely glorious in a gentle breeze which results in a light swaying.
However, there are some major downsides.
CONS
--They are less than worthless in really windy conditions.
--You will freeze your posterior off in cold weather. They do not retain heat well. All wind blows straight through them.
--It is a royal pain in the posterior to get in and out of your sleeping bag once inside the hammock. Hope you don't wake up needing to pee urgently in the middle of the night.
--You cannot always find trees the appropriate distance apart (12 to 20 feet I believe). You must be familiar with the area you are going to before you go.
--Personally, I find that they take two to three times longer to set up as compared to a tent, although with practice you can improve set up/take down time. It takes a while to get the height and tension adjusted correctly. You can't just "save your settings" from last time. The distance apart and diameter of the trees involved is different each time. The slope of the ground constantly varies.
--The places you want to use them the most (due to heat) may not have trees to support them (Death Valley, Joshua Tree, Baja, Anza-Borrego, etc.).
As to hammocks, if you could include in your comments:
-- Do you use the hammock type with Velcro door?
Yes, and the Velcro door in the floor of the hammock works quite well. Easy in, easy out, keeps out the bugs (there is mesh above the sides of the the hammock which also keeps out the bugs).
-- Practical for more than 1 season? I hear they can be chilly.
Chilly? How about frickin' ice cold? Only good in fair weather in 60's or above. I've been fine in 50' weather, but you're pushing it if a wind comes up and you're using a down bag.
-- Comfortable?
Very much so. Delightful in fact.
-- Do you find campgrounds with trees OK?
Generally, but sometimes it's a stretch. Do your research beforehand.
-- Have you run into areas with tree rules that prohibit tying anything to trees?
I never have.
Let me close by saying that hammocks are great in warm, fair weather conditions when you're not in a hurry to set up and take down.
HJ
If you had ideal conditions (two trees of exactly the right diameter at a perfect distance from one another over completely flat, non-sloping ground with no brush or obtrusive branches with warm weather and no breeze), and you drilled and drilled and drilled yourself, and you weren't too particular about having a taut support rope, then maybe, just maybe,