I'll add another con.
As much as I like my UQP (I got a nice camo one) and take it everywhere, if the wind is blowing moderately hard it will inflate the UQP and pull it off the hammock/quilt assembly turning it into some kind of kite surfing thing nowhere near the water. Less when I'm in it than when I get out for a moment.

For us wind is the norm, right up there w/ high UV destruction, and I AM going to figure out a way to prevent it pulling of the protector.