If only we could walk in a bubble where we stay dry and the rain falls all around us. I have participated in so many of these threads, looking year after year for the best rain gear and have finally decided that it is an impossible dream.
https://www.caminodesantiago.me/community/threads/wet-weather-clothing.35680/#post-331453
If what you read on line or hear from experienced long distance hikers is true, none of this will keep you dry when the rain is endless.
http://sectionhiker.com/why-does-rain-gear-wet-out/
I think the choice in rain gear depends on whether you walk in warm or cold seasons. If you walk in fall or winter, then something like the Ferrino makes sense, because it has a metallic lining whose function is to increase/maintain your body temperature. Of course if you walk in the Ferrino when it's warm, increasing your body temperature inside your rain poncho just leads to a pool of sweat. I was so happy when I got my Ferrino and wore it on the Levante, which I started in early May. We had one or two sustained rainstorms, and I saw that within minutes of the rain starting I was sweating inside my Ferrino. SYates later informed me on the forum that it was because the Ferrino metallic lining was doing what it is supposed to do, that is increase your body temperature. Great, but hypothermia is not a problem in southern Spain in May!
If you walk in summer, something with lots of vents for body heat to escape seems to be just as effective as those expensive gor-tex Marmot clothes, the
Altus poncho, etc etc. I have a collection of raingear, expensive and cheap, that could fill a small botique. According to some pretty savvy hikers I know, people who don't sweat inside their ponchos are either not producing enough body heat to cause condensation or are walking in rain that hasn't reached the saturation point of the outerwear yet, or both. That suggests that slowing your pace may be a good way to keep you dry inside the poncho, but then of course that means that you are walking longer in the rain! But hope springs eternal, and I'm not opposed to continuing the search for perfect raingeear.