Ponchos are useful for everyday commuting because it will fit over whatever you happen to be wearing, and most people don't go too fast on their city commute. But for touring, spending hours a day on the bike, the wind resistance becomes a real drag (pun intended). I have a Showers Pass rain jacket, and it's wonderful. Wool t-shirts and heavie long sleeve shirts keep my warm and dry underneath the rain jacket. Also, having a rain-cover for your helmet keeps your head very dry and very ventilated.