Given reviews from Amazon, classify those review based on their content into two classes: Negative or Positive.

Let me give you an example: I've read this book with much expectation, it was very boring all through out the book
The answer to this example can be: Negative
Here is why: Review writer does not like the book because it was boring, therefore it is a negative review.

OK. solve this:
Mostly very happy with this product, except the fact that it's dreadfully slow on fast forward or reverse. As you might imagine this can become very frustrating at times. And also totally unable to skip ahead to another part of the recording immediately similar to what the ipod can do.---C'mon Sandisk, give us some software to correct these serious inconveniences!!
Answer:
Positive