Great resource for Gmat prep.

Quants:
The videos include all the topics required to take the gmat effectively. The list of practice questions is also extensive and should suffice to score a q48 and above. one must go through the video solution of the problems which were difficult to solve.

Verbal;
SC is very well explained , the problem set in sc is also a great resource to understand the concept and build speed. Again go through the video solutions if you find any problem difficult.

CR and RC are above average. Not the best but are enough to build strong conceptual foundation .

The CAT provided with the premium service is not upto the mark and i would highly recommend to get a third party CAT series for testing and tracking your progress.

All said , Magoosh is a great tool to build a solid foundation and score a 620 on the gmat fairly easily .