The best parts are the listening and writings, the speaking part is not an excellent source for improving your speaking skills for Toefl unless you do it without paying attention to the suggested answers ( which usually are not committed to the time limits)
I used Longman some time ago, it was quite resourceful. The content was really close to the real test that you may face. The strong point is the reading, vocabulary, and writing. A lot of vocabulary were provided, enclosed with different readings. Also, the writing part was deliberate and clear. I think the listening and speaking sections were above average. I advise you to refer to Longman if you want to perform well on this test.