No mention of ponchos in this article. I have tried different raingear system and am a convert to the 200g mountain poncho described on this site. I had it sewn to cover the groin area. This is perfect and sufficient for 90% of rainy conditions. Superb ventilation, speed of deployment, and ease of use (particularly doing various tasks while walking go without stopping). I can even tuck my head and arms inside and look at maps without taking it off or worrying about getting maps/smartphone wet. In colder rain I also take MYOG silnylon chaps and VB socks. The whole combo weighs about 300g and is a LOT cheaper and, I believe, more practical than the systems reviewed here.
Also, regarding handwear. I am a believer in mitts with a retracting finger box. It's inconvenient to have to keep taking off the gloves to do tasks (poking smartphone screen for map reading; clipping flashlight to tarp clip; assembling stove, etc.). My moderately windproof fleece mitts are so much more convenient than PossumDown, as much as I like the feel (and they also require an additional windproof layer for cold/very windy conditions).
I realize that preferences differ, but these are mine after a year total of mountain backpacking over the past 6 years :) Among the items/systems I've rejected are: poncho-tarps (2 models; clumsy tie-out storage; poor poncho functionality), eVent rainjacket, goretex socks (stinky, slow dry), rain mitts (for most conditions at least, I now just tuck mitts into poncho sleaves or use umbrella), merino wool baselayers (low insulation quality per weight; unduly expensive, nondurable; switched to PowerDry baselayer and very pleased after 100+ days of use).
NOTE: I'm referring to Roger Caffin's "mountain poncho" design, for which MYOG instructions can be found in a detailed article here at BPL. It's suitable for any kind of rain, including horizontal.