In order to truly 'run all day' you would need a receiver pack that lasts 4-8 hours. What you really mean is you can run tank after tank for a few hours and then you need to charge up your receiver pack for who knows how long.

After a year or two, when all of those gallons of nitro feul have been spent, guys who run electric you will have accumulated several packs. Some will not be good for racing but still have plenty of power left for practice.

Somebody with 5 3300 packs can easily be running for 30 - 40 minutes each hour. I know, that is not as good as nitro, but, I'm not exactly sitting on my hands either.