help visous fan worth it or not???

When I installed a new aluminum radiator last summer I could no longer use my Mopar viscous fan because the new radiator was too short (the radiator is only 16" tall and the fan is 18" diameter so it overlapped too much to use a std. shroud). I thought about what was the best alternative, a flex fan or an electric fan. Since the flex fans design flattens out at speed it seemed to me it can't produce much drag. The electric fan on the other hand consumes electricity (some suck a bunch of amps) so the alternator has to work harder to keep the batt charged. Considering how weak the electrical system is on our cars I decided to use a flex fan. I don't have a before and after comparison on a dyno but I can say by the seat of the pants I can tell no diff. in how it runs. Gas mileage doesn't seem to be any different either. Not saying the viscous fan doesn't work, just saying it's a probably a very small gain. JMHO