I fragged my mechanical fan at a competition and a buddy gave me a new in the box electric fan.  I made a shroud so it bolts on all nice instead of using the zip ties.  I used it because it was cheaper at the time than sourcing a new stock fan.  I don't notice any seat of the pants HP difference or mileage but our property has the driveway flooded with about 3' of water and it sure is nice to be able to shut the fan of to keep from flinging muddy water and chunky floating foliage into the engine bay.