See my suspension weight thread, it gives a pretty good look at the differences when it comes to weight.
For me I went from webbing to whoopies, (thinking that I would save weight) but the frustration level of using them, made me turn back to webbing within in a year.
As far as a trees here in the PNW I ordered a "custom" set from Brandon at WB I asked him to make me some 20footers, and they work great. Haven't had an issue yet...Some times I do carry and "extender" kit which are 2 6ft whoopies, which I can use as part of the tree strap system so that the webbing can still go through the buckles.
Webbing, to whoopies, to single line......
And finally back to 14ft. webbing with that Dutch on rope 1 buckle. I usually have an amsteel extender thingie
I'll be putting the srs suspension on my new hammock I hope to finish tomorrow. 5-6ft straps are good for most places I'll be, if I can't hang from one tree because the tree is too wide, well... move to the next one, another great thing bout hammocks, almost unlimited spots to 'pitch'.