I've only watched one Formula E race, and that was probably over a year ago, so my opinion may be outdated.
The race I watched was set on city streets, which put severe limits on the speed of the cars, as well as making the race course rather cramped, and there was no place for watchers to get a good overview of the entire course.
Just as bad or worse, it was set up as a sort of relay race, with drivers jumping out of one car and into another, because the cars' battery packs didn't have enough energy for an individual car to complete the race.
But the worst part IMHO was the "Fan Boost" situation, where fans cast votes by phone for their favorite drivers, and the winner gets a boost of more power available from his battery for a short time. IMHO this turns Formula E into a sort of popularity contest, rather than a real race.
According to what I've read, in the last Formula E season at least the cars were expected to finish the race, altho they have to limit speed so the battery pack doesn't run out of "juice" before the race is over. But so far as I know, they're still doing the stupid "Fan Boost" thing.
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Here's what I'd like to see; here is what would get me to watch another Formula E race:
1. Get rid of "Fan Boost"
2. Allow unlimited battery pack swapping in pit stops during the race, in the same way that gasmobile racers can refill their gas tank in pit stops during the race. This would let the cars unleash their full power and speed. Also, perhaps it would actually be beneficial in developing practical battery pack swapping tech, which currently is pretty expensive and possibly over-complicated.
3. Hold the races on a proper race course, ones with enough room for the cars to get up to high speeds, and in places where it's possible for onlookers to see a large part of the race course. EV racers have the potential for better acceleration than gasmobile racers, and it's terrible how Formula E races are held on cramped, narrow courses that cripple the cars' ability to accelerate and maneuver.