Iv owned both the i3(standard not pro) and e-vents heres a comparison of them both.
Dye i3 pros:closer fitting, more padding and more venting
Dye i3 cons: hard lense change, smaller pheriperal vision than the events
Empire E-vent pros: larger lense, quick change, soft ears, comes with 2 lenses
Empire E-vent cons: less venting, less facial protection
Hope this helps, check pbreview for some more info
Nathan