Instruct: Classify the given review as either positive or negative.
Query: Not as happy as I'd hoped

I had the "old" version of this grill, that did not have removable grill plates. I'm lazy and thought the removable ones would help me keep it cleaner....well, it is cleaner, but I doesn't cook nearly as well. With the "old" one, I could take a rock-solid frozen chicken breast, pop it in and in 12-15 minutes it was done, and perfect! Now, the outside gets tough and the inside is barely cooked. I can't explain this, as it looks like the same heating apparatus, etc, but it happens consistently. I'm thinking of switching to another grill. Seeing as I don't use it that much due to poor results, what good is the fact it's easier to clean?!?