BarateGites - thank you for your question. My advice would be that you try out both TTP and e-GMAT. You are already familiar with the TTP format. Given the nature of the topic, you may benefit more from
1. Video-based learning
2. Meaning-based approach.
Since you are already aware of most of the concepts, you should be able to complete the SC course in 15 days. One other thing - e-GMAT is designed for working professionals. The built-in personalization helps you focus your energy on areas where you need help.
For CR and RC, we can also provide that last mile push to help you achieve the 90th percentile. We power those journeys through our Scholaranium product. Here is one of many such examples:
I would also recommend that you check out our reviews on GMAT Club. In June, we accounted for ~70% of all reported 700+ scores. As you read the reviews, you will realize that these hyper-specific improvement plans are a driving force behind these successes.
Good luck!!
-Rajat