It sounds like you're very busy, but if you can carve out 30 minutes a day, why not do both and alternate them? It would be a 60DS instead of 30, but the benefits would be better running results.
I saw results very quickly when I did the C25K in terms of pounds dropping from the scale, but it was when I added the strength training to my program that the inches dropped even when the scale didn't.
Or you could do the 30DS 5 days a week and add in a couple of long runs. But if you aren't already a runner you might want to keep to the 3x a week run schedule to build endurance.
As for feeling like you're eating more, just keep a food journal. As long as you aren't feeding your body junk (or even eating massive amounts of good food), that extra food will be good for you in the long run. You'll have more to fuel your workouts.
The need for extra food did taper off for me about the seond week of C25K, it was like my body realized we weren't actually enaging in the "Flight or Flight" response. It was like "oh, this is supposed to be FUN", not "oh, we're running for our lives". Did that make sense?