Whether to bring a poncho or a rain jacket is a matter of preference - and much discussion.
I like the Ferrino Trekker "poncho" (it's actually a coat), which performs brilliantly in gusting winds and sleet, while also covering my pack. The "new"
Altus, I dislike very much. The only Packa I've seen, didn't cover the bloke's rear end, so he looked like he had peed in his pants.
In a strong head wind, any jacket or poncho will creep up over your knees, so for the legs, I use a pair of rain leggings, that leads the runoff below the top of my boots. The rain leggings also allow me to use the shorter (and lighter) small/meduim size Ferrino.
A rain jacket should be combined with either rain pants (don't you simply love walking with a clammy crotch?), or a rain kilt. It should also be combined with protection for your pack. I don't trust rain covers, as the straps wick the rain down your back and into the pack. A much better solution, is using a pack liner (which, if kept closed, also keeps bugs out of your things). Personally, as a carry-over from wilderness hiking, I prefer using dry bags for the things I want to keep dry - one for my clothes and one for my sleeping gear - even when using the Ferrino.