I'd be really hard pressed to find someone with greater control over electromagnetic energy then magneto... and as there really isn't a way to draw a comparison... seeing as 'energy' electro never fought anyone could could repulse, repel, or manipulate his own power..
course i have seen magneto forcefully tap into and use against their wills as powersources... joseph... and polaris...
so i'll say that magneto is very adept at tapping into electromagnetic energy sources... and that he can find a way to manipulate electro..