Here in central Brazil we have desert-like conditions in the dry season. Last year I tested the various water collection methods with the following results.

The solar still produced a great deal of heavy condensation but very little actual water, about half a cup.

Transpiration bags produced about an ounce each. Unfortunately the plants in dry eason just don't contain a whole lot of moisture. FYI I was just back at to that ridge this week and the branches that I had attached the bags to are now dead. Some tips, remove any bugs or leaves with bird poop on them first to improve the water quality.

Dew collection in the early morning yielded 1.5 liters in about 45 minutes. I used a 20 x 30 hand towel and started with the dew that formed on my small BP tent. The abundant grass in the area also yielded a grat deal of dew. This water was a light brown and had to be treated heavily with iodine.

Seeps here are easy to find, a small dig will produce liters of water in short order if you scouted the location well. As dry season drags on these are harder to find and you have to dig more. It is wiser to use that sweat to keep walking downhill searching.

I concluded that the solar still, if used at all, should be the end game of the water collection strategy. Suppose walking downhill looking for seeps or flowing water didn't pay off and you were forced to dig in a likely low spot. If that didn't produce ground water it may produce soil moist enough for a still. Anyway the hole was already dug with the prospect of ground water in mind.

Dew collection alone could have sustained me easily producing 4 liters of water if collected at night and just before dawn. The water is pretty nasty looking though. Mac