Originally Posted by Hepar

2nd that. High MP's are just something that the camera companies push because the base consumer will relate it to quality. My Nikon D700 was a 12.1 mp camera and the somewhat low sounding mp count is one of the big reasons I chose it. It combined with the large sensor meant much less noise at high ISO (the more mp's you cram into a sensor, the more mp's will be effected when you bump up the ISO) as well as giving the camera itself a faster ability to process information, thus being able to shoot much faster.

My current D800 is a 36.3 mp camera and while that sounds great, it's really not. The file sizes are HUGE, it's shoots much slower than my 700 (4.5 fps vs 8 fps) and it processes pictures much slower. I rarely need the resolution the 36 mp's provide and would have been much happier if they kept it down under 20. But I needed video...

Sensor size and quality are much more important.