I use a treadmill to do the C25K! I dont have one in the house yet, but have been contemplating it recently. My recommendation for you for C25K, is to not start off too fast and if you feel you need to lower the speed than do so.
Its easy to go to fast on a treadmill starting off. Also, do some of your runs outside so you can get a real feel of running foot to ground. Some of the best advice i have gotten. My first 5k is March 12th. I will start week 8 this week! Pretty exciting!
Youll def drop some pounds, since i started the program i have lost 16 pounds, and am overweight and running 25 minutes straight! Makes me feel like a badass! Good luck with the program and dont stop, just keep pushing through it, if you feel you need to repeat days do it! Its worth it!!!!