« on: February 14, 2010, 12:28:47 pm »
I have an old ThermARest standard self-inflating mattress and a newer Big Agnes mummy-shaped inflatable mattress. The cush of the BA is awesome, but if you plan on using it for very cold weather outings, forget it. It's COLD in the snow! (or use a cheap blue foam backpacker as the insulating layer) The old TAR is still very good in cold weather, and continues to provide moderate cushion.
If you never plan on using it in the snow or on frozen ground, the BA will probably give you a better night's sleep, especially if you sleep on your side. Get the rectangular if you toss and turn. I have to wake up to re-position on the mummy-shaped one since my feet and hips seem to fall off.
Fully deflated, the BA is small enough to pack into your bags.
I've never had a leak on either of these mattress types.
Keep in mind that there are thicker (and more expensive) TARs than I have, so if you can afford one and need the warmth, I'd go for a TAR thickie I'm more than happy to pack the pad on my rack with my sleeping bag. If you don't need the warmth, the BA will do nicely.
In short, BA gets points for cush and packability while TAR gets points for warmth.