People coming from science and engineering background tend to go for Brilliant tutorial material for preparation for civil services due to their familiarity with the same during their preps for entrance exams. Ready reviews about the material is not available in the internet. This is my experience from using their material for my preparation for prelims and mains of CSE-2010.
Science optionals: I had physics as my first optional. The preparation for any optional should be ideally from a mains point of view. Besides, you need to master all the topics for the science optional due to scaling and the ‘almost digital’ marking scheme. Thats were the problem starts with BT material.
1. Not all topics are covered ( This cannot be afforded as each question in the paper will consist of 3 separate questions in a 20×3 format. If you don’t know one sub-question, you can’t completely attempt the question) . I found often repeated topics like Rayleigh scattering, Difference between conductors and insulators by quantum method skipped.
2. The approach for a lot of questions is not the standard one and wont fetch you 20 marks if you attempt.
3. Concepts are not properly defined in the beginning of a proof. Besides, they skip a number of steps in between and bring in unknown concepts without introducing. This is fatal as it will hamper one ability to study and remember the derivations. Conceptual clarity is given good weight during evaluation. One will end up writing bad answers.
4. Glaring mistakes in many solutions.
5. The change in syllabus has not been incorporated. The result: a lot of crap.
The only good thing that BT material gives you is that, appended to every chapter is a question bank of all previous questions from 1990. This is very important in knowing the pattern of questions and to fine tune ones understanding. Although the question papers are available at examrace.com, in the early periods of your preparation, the solved set can be a real boon.
I was studying optics from BT material, found it hard to continue and then found out the wonderful book by Ajoy Ghatak. I studied Electricity and Magnetism from their material, then had to relearn the chapter from textbooks after failing to answer questions asked from the chapter in the previous years.
So what is to be done? Use standard text books alone. Supreet Singh Gulati has written a good writeup on the textbooks in his blog.
Non-science subjects: The material for all non-science optional and GS is a big time mess. The material is completely out of focus and it’s really hard reading through it both for the lack of conceptual clarity and the low quality print. The material is filled with copy-paste kind of material from all possible sources which has no relevance for the exams. They have science section for GS which deals has given the topics studied in plus 2 like thermodynamic, scientific names of all possible organisms and what not. All the model answers given at the end are just general comments which beats around the bush. A conceptual flow and connectivity that’s vital for subject like PubAd is hopelessly absent.
Concluding, if you have a science optional, the question bank can be useful but that doesnt justify the 15,000 rupees one has to pay. But if you are not taking a science optional, subscribing for BT is throwing your 15K down the drain…