I use frozen meals for my lunch or dinner a few times throughout the week. I'm actually eating one right now. I know the sodium level is high so it's one every other day or so. They are tasty and there are a lot of options especially if you don't want to cook.
For the other meals I have fruits/veggies/water and bran/oats and low cal almond milk (love it!).
So far I'm down 40 pounds in the last year just by switching to small portions and not eating ice cream everyday (but I will never cut it out completely...).
I tried a nutri-system 7 day starter pack from walmart once (it was $40 which is a bit to stiff for a college student...at least this one haha). I honestly felt super hungry on that diet and it made my sugar cravings terrible because of all the chocolate flavored things.
Overall I think these meal plans are a great supplement but I think it is too pricey and boring to just rely on it alone.