Does mounting a oil catch can below the engine hurt performance, and why?

I'm planning on mounting mine below the battery and in front of the coolant reservoir in my 02 trans am. I can't think of any downside, but can think of many upsides. (cooler air hits it, less cluttered engine bay etc)

Does anyone know why you wouldn't mount it below your engine? and why? Not looking for two word "it's bad" regurgitated answers.

 

My buddy had his mounted on the inside front framerail on his 8 sec bird don't see any downside to it.