I bought the ultimate prep package which comes with 70+ point increase guarantee I got a 650 on my first practice test. This was my baseline score.
I had 7 days of free trial before I pay for the course. At the end of the free trial I completed almost 10% of the course and was definitely convinced that it's worth spending.
Overall, the course content and methods explained in both Verbal and Quant were very helpful. I was comfortable with the format and my course progress. However, 25% down the course I took the second practice test and got 640. This got me worried and I decided to use the live strategy sessions with GMAT tutors. I got some good advice from Isaac who helped me improve my time management issues. Although, it took me 2 more GMAT practice test to figure out the most optimal way to manage the time, once I figured my score was consistently over 670.
I scored a 690 on my last practice test with Economist and scored 690 and 710 on 2 mba.com tests. Eventually, on the D day, I got 690 (V33 Q50).
I was able to cover most of the topics (although took me 6 months since I am a busy full-time working professional). The tests were great and similar to the real test. Also, the live sessions were helpful in assessing the practice tests and discussing customized strategies based on the performance.
Overall, my experience with Economist was good. I would recommend this course to people who are busy working professionals and prefer to prepare at their own pace.