If money and time is not a factor then full-time preparation is always better. If time is a concern, try weekender courses.
Going through the full time course at least once is a benefit, especially in situations where you are not able to crack the exam in the first attempt. At least you are able to understand the pace at which one must study, what one must study, what the competition is like etc. For subsequent attempts at the test, simply going for the online version with mock tests suffices the purpose.