AdSense Ad Units (one or many)?

[alfuzzy]

<u>Here's the hypothetical situation:
</u>
Example A: A website has 10 different ad locations...has 10 different (unique) AdSense Ad Units...and each ad location has its own unique Ad Unit.

Example B: A website has 10 different ad locations...has only 1 AdSense Ad Unit...and this single ad unit is used in all 10 ad locations.

Other than not being able to do Ad Unit customizing by ad location in Example B...are there any issues using the exact same AdSense ad unit in all 10 ad locations (less revenue?, more revenue?, no revenue difference, better fill rate?, lower fill rate?, etc.)?

Thanks