Yes You Can! With the *new* BTG questions.

Want to practice only SC questions today? Have time to do only 10? Yes you can!
Have you mastered the fundamentals of Probability and want to target today's practice session only on 700+ level questions on the topic? Yes you can!
After a review of your error log, do you realize that you really need to work on those Weaken type Verbal questions? Across CR and RC? Yes you can!
Do you always get Integer Properties questions wrong only on the DS section? Have all day to work on it and want an (almost) unlimited supply of questions to be thrown at you till you crack it? Yes you can!
Tired of going through consecutive questions in the Official Guide which are at the same difficulty level? Want a practice session where the questions thrown at you are in an adaptive format? Yes you can!
Have you run out of CAT tests and want to create one of your own? Yes you can!

BTG has managed to create an (almost) perfect product. If you've run out of OG questions, and even CAT tests, this product's for you. [This is an improved product from BTG which is to be released today, November 2nd. It can be found here].

Totally customizable
Every practice quiz you take is totally customizable to your preferences. You can choose which section you want to target (Math or Verbal), which type of question to target (CR, RC, SC, PS, DS) and even the topic of the questions (Idioms, Weaken, Arithmetic...)!
You know what else I love? You can choose the number of questions you want to answer!
Have time only for 10 questions today? Your boss suddenly interrupts you during the 5th question with urgent work? No problem! You can choose to end the practice session there and see your results.
And this part, my fellow readers, is what I call an absolutely brilliant feature - the difficulty level. You have a choice of below 400 questions only, all the way upto 700+ level questions. And, that's not even the most brilliant part. Have you heard of..wait for it...adaptive questions on every quiz?! This one made me super happy!
A timer on the right hand side tells you how much time you've spent on the question during the quiz.

Create a New Test

You can choose to answer 37 Math questions, in an adaptive format. Once you've ended your session, head back to the "Practice" tab and create a session for 41 Verbal questions (adaptive mode). A brand new test has been created! :) You can also randomly pick any topics for the 2 essays from the OG, and you're all set to give a full 4 hour exam at home!

A breakdown of questions on each section

Math -
I found the difficulty level of questions pretty reasonable, not extremely easy and not so difficult that you'd never be able to crack it in 2 minutes (under 3 minutes for the really difficult ones).
Verbal -
Pretty much the same as for Math...

The Video Explanations
A friend of mine wanted to practice some SC questions and wanted me to help him out with understanding where he was going wrong. So I called him over to practice from my Reviewer's account of BTG questions. Once he was done with the questions, I realized I didn't have to say a word to explain his mistakes to him! The video explanations did all the talking! They even taught us a few things we didn't know, such as idioms that I wouldn't have caught if I was trying to explain it to him myself.
The Math explanations are clear, and I didn't find myself requiring any further explanation once the video was over.

Review
The review section is pretty much the same as you'd find in any other similar product. But there are two parts that stand out for me:
First is the colour of the amount of time you've taken to answer the question. The colour is different according to whether you've outpaced others who answered the question, or were slower than them.
The second is the flagging the questions feature. In case you want to review the question again (irrespective of whether you got it right or wrong), you can flag it. What's the point of flagging it, you ask? *sly grin*

Prepare yourself for...

Super-Customization

I was feeling pretty content and happy after having customized my practice session down to the topic of questions I wanted to answer. But before I clicked on the "Start the Session" button, I saw blue text that said "Show more options". More options?
Here they are:
- include questions that I have already answered (after going through 700 questions, are you really going to remember them all?)
- use only flagged questions (yup, include the questions you got right but should still do again)
- only use questions I got wrong (for obvious reasons)
And yes, you can select all 3 at the same time also.

Definitely worth it if you've run out of questions to practice from, or want to customize your practice sessions exactly according to your needs (especially if you want to do this!). I had hoped such a product would come out for OG12 questions (and it's Verbal & Math supplements) so that I could practice questions from those books in an adaptive customizable style. I hope this great effort from BTG gets a similar product out for Official questions soon! :) Till then, enjoy the power and remember, with BTG questions, YES YOU CAN!

PS. BTG is giving me a couple of subscriptions to this new product to give away. While I'm giving some to my friends who're also giving the GMAT soon, I might have 2 accounts left over to give away. So I'll do that on a first come first serve basis. HOWEVER, I will also snoop around and try ensuring that you don't already have an account that's been given away (I have my sources! :p). Once I'm satisfied that you do need one, I'll send you access to it! :)