Ask HN: Any feedback on interview bootcamp www.interviewkickstart.com

For those who don't know, www.interviewkickstart.com is a interview bootcamp. I am considering using them for preparing for interviews. I am good at CS fundamentals but suck at interview coding. With life being busy, I am not getting enough time to prepare. And companies have become crazy today. Even if the work is to make a CRUD app, they want you to design a OS in the interviews.

Has anyone here used them for their interview preparation? Any feedback on the structure and its utility will be appreciated.