The best custom Quizzes!

As I had purchased the MGMAT and Veritas mocks, I used GMAT Club test quizzes for topic-focused practice.
Here is the list of things I found most useful
1. Fully customizable quizzes as per the topic type and question type.
2. Quality GMAT level questions.
3. Very short and to the point solutions that are very useful for the tests like GMAT. The official answers are very lengthy and not pragmatic.
4. Direct link to the forum discussion.
5. UI is almost similar to actual GMAT.

Some shortcomings
1. When I selected all difficulties I usually got most of the question from 500-600 level and very few 700 level questions. There should be an option to select the number of questions in difficulty option.
2. Quizzes are not adaptive.