"300 dpi gives you a higher quality render then 72 dpi"

The dpi question gets discussed every few weeks, and there's always someone giving out wrong info about it. The fact is unless you are working in real world units like inches, the dpi makes absolutely no difference to anything. It's just a tag stored in some image formats for printing purposes.

Renderers only deal with pixels, and the pixel resolution are the only numbers that matter. A 512 x 512 pixel render at 300 dpi has much less quality then a 2048 x 2048 render at 72 dpi. And a 2048 x 2048 render at 300 dpi has the exact same quality as the 72 dpi one.