I guess it depends on the team I'm using. My problem when using Manectric is that I always seem to be in a position where I can't safely mega evolve because I won't outspeed on the first turn (since you don't get the speed increase when mega evolving until the next turn).
It's also worth adding that Manectric does have Lightning Rod to switch into Electric attacks and get a free +1 in SpA.
I don't know. Manectric may be better, though I still hate it and will continue to be biased against it just because you use it.