I started IP on April 7 this year and it's worked really well. I'll stick it out until I'm done. I've had two planned cheat days, and I'll likely have two more before I'm done. Haven't had a problem getting back into ketosis either time, and I think it's good to shock my body a bit.
15 weeks on IP, averaging over 5 lbs. a week. Hoping to be on maintenance in time to buy my new wardrobe for my birthday.