i've not yet owned a hammock w/ netting but i agree w/ what's been said... depends on when & where you're at as well as your body chemistry.
there have been several times i wouldn't have minded having one, for those pesky gnats if nothing else.
and w/ some of the stuff you can end up w/ if the right critter bites you, it's probably a good idea to have one or more forms of protection.
i have plans to make a hammock w/ a net that can be put away when it's not needed.
don`t leave the CREATOR out of the creation!