Almost the real deal!

I purchased the Experts' Global 15 mock tests and these were the only mock tests I used.
For reference: I consistently scored between 710-740 in these mock tests. Scored 710 and 730 in my 2 official mock tests. Finally got a 720 in my actual GMAT. The +- 30 buffer is common for every mock test out there.
The analytics after every test is just brilliant. It helps you keep track of the areas you're missing/ taking more time in.

One more thing that I'd like to highlight is the 'GMAT Shots' that come with the 15 mock tests purchase. They are short concept videos for all sections and are pretty good for concept revision.

On a whole I would rate it 9/10! Great purchase!