Did any one try the SlaythePE free PE Practice Exam?

Hi guys, I hope everyone is having fun for the preparation of the exam. 

I found this Free exam online SlaythePE, which has 80 problems and they claim it is the same format as the new spec in 2017.

However, you need to pay $80 to get the step by step answers. (sorry to disappoint you).

My questions are:

1. Did anyone purchase the SlaythePE practice exam answers? Are they helpful?
   
2. How is that in comparison to the 80-problem practice exam by Justin Kauwale? ($40 only) 
   
3. What other resources of practices problems besides the 2016 NCESS practices exam and the Six-Minutes Solution do you guys recommend?  (I assume most people have both)
   
4. What about the Mechanical PE Practice Examination (MEPE3) by Lindeburg? ($68)
   

Thank you all and enjoy the rest of the study!

P.S. Their site also has other useful stuff, i found the Mach Number chart is pretty cool.

http://www.slaythepe.com/free-resources.html

Hi Eric

Thanks for linking to our site! We're glad you found some of the free resources useful. We agree that the graphical form of the compressible flow tables is neat.

Remember that when you purchase access to the solutions to our exam, you get email access to help on any of the problems. This means that if the written solution is not clear enough we can provide more thorough explanation/discussion via email conversation.

Cheers!