I’m French and recently took the TOEFL required by my MBA application.
Some figures : I scored Q:90 and V:70 on the GMAT and 4.5 on the essay section, 111 on my TOEFL (R:29 - L:29 - S:23 - W:30)
1 - I consider that my level of English was the same for both exams. That means that the TOEFL’s level of assessment for the writing section is much lower than the GMAT’s.
2 - I prepared using Kaplan prep books and CDs without a teacher (I borrowed this material from a friend). I did all 4 complete exams and consistently scored around 25/30 on listening and reading questions. I believe that the level of difficulty (tests and questions) was very similar if you compare the Kap prep book and the real test content. My conclusion : while the estimation of your score on prep books is done quantitatively, your real score on TOEFL depends on how well the others do. In other words, my raw score certainly was around 25, but I officially scored 29/30 on reading and listening sections.
3 - It really helps to get an idea of the length of the test. Even though TOEFL and GMAT do not play in the same stress category (GMAT much harder), TOEFL is a bit longer and you must stay concentrated till the end. To perform real length tests helps you become familiarized with the type of questions you’ll face on test day.
4 - My speaking score is not as good as the other scores although I do not consider myself a bad speaker. I guess this section is the most difficult one to prepare, since you can not easily get an external assessment. I’d recommend to find an English native speaker and ask her for an expertise of your level. Once again, get prepared about the standard types of questions.
5 - Essay tips : you must write very quickly with a minimum of grammar mistakes. Furthermore, you must respect the essay rules : strong introduction, clear and distinct paragraphs. The first essay is a summary of a reading vs a listening. Stick to the 225-word direction and be precise. The second one is a free essay on a familiar topic, be convincing and be lengthy (around 400 words). To achieve that, I’d recommend to learn sentences by heart (especially for the introduction and the conclusion). You’ll find those sentences in any prep books. I see 3 major advantages : you go fast, you go 100% right and you structure your essay. I was very impressed to get a 30/30, to be compared with my 3.5 GMAT first attempt and 4.5 second one (same method).
In conclusion, TOEFL is really a test worth a solid preparation (you need to complete many, at least 3, full length tests and get a perfect knowledge of what you’re expected to listen, read or write.
Good luck to you all
TOEFL listening discussions: Why must the young woman leave?