Summary: very good computer. the processor is nice and setting the gpu to certain programs it's helpful for battery life. the Wi-Fi seems unreliable to me and doesn't perform well enough for my online game.
Summary: Low power CPU's are usually more expensive and have lower speed. Most of MacBook Air use these family of CPUs. If you want higher speeds, then it will overheat like an oven where you can fry an egg. So, choice is yours. I prefer low power CPUs. Now they are able to make up to 2GHZ and 3GHz in turbo mode based on current available technology.