I wouldn't say it's great for dieting, no, as it's NO cutting food, that's for sure. There are better choices for that time in your fitness journey.
For maintenance or bulking, it's fine. But those in the know, understand that dairy is a no no when trying to get the most hard physique possible. Many will yap and say "but it's great, it's high in protein, blah blah", but until you step on stage and compete, model, etc., you'll understand why dairy is eliminated. For those very serious, it's avoided.
~SC~