FOV (field of view) is different to DOF (depth of field). The field of view is better with the EV than the Mamba maybe not the DOF, although i suspect they are very close.
The one hundred yard "thing" your on about is irrellavent to most Airgun shooters, close (8yds) to long range (55yds max) is what we are on about. I understand that not all are airgun shooters but i would have thought for powder burners a higher mag would be more benefit due to the increased range a shot can be taken at?
I don't shoot bullet rifles so can't comment on the shooters needs, but for Airgun hunting and HFT is a cracker for a cracking price.