Thanks everyone. That info helps. I think either the NX-250 or the TX-250 would be just fine, but I want to get what will work best for me. The NX is a little heavy for my lightweight backpacking but its in the range. The standard XL tarp it comes with is too small for me and the tarp upgrade makes it even a little more too heavy. I'm a lightweight backpacker and I don't ever carry enough "extra" stuff to fill six pockets enough to insulate me. All my extra clothes would probably fit in one pocket.
1) Does anyone know if the optional weather shield on the TX-250 zips completely off and can be left behind. i wouldn't need it much and the weight savings would make a big difference.
2) Does the added bulk of the largest tarp still fit in the self contained compression wrap or do you need to put it in a separate stuff sack? I would guess a separate stuff sack might be advisable any way if the tarp is wet.