I have the Hennessy Safari Deluxe, and I went into a 'Big Agnes'
The principal of the Agnes bag, is that it has no insulation on
the bottom, just a 'sleeve' that you slide some kind of pad into.
Air mattress, therma-rest, etc.
I got the infamous target pad, had to reduce the width by about
5", slide it in, and off to dreamland.
It works pretty good, there's basically no sliding off the pad,
because it's integrated into the bag. It makes it easy to maneuver
within the hammock, you can slide your whole body around easy (nylon
on nylon), and you can't lose the pad.
I recommend it.