Anyone have experience working with them? 

It seems like you are either taking bad experiences that you have had, or things you have heard, and you are blanketly applying it to entire strategies that have worked and been helpful to tons of people. 

If yes, what was your experience? 

Which market do you have experience in and how is your experience working remotely with your real estate team in the area?  

In my experience, cost segregation studies are a lot less than $10-15k especially for smaller properties (6 units and below).

Look for one that has other listings and experience in the area.

I would have been ok with the latter numbers because I have been stockpiling materials for like two months, but...I did not know if I could trust them due to the lack of "professionalism," and my lack of experience. 

Quote from @Jerome Brown: Hey BP, My name is Jerome Brown and i have some real estate experience.

Quote from @Zack Marshall: Quote from @Tyler Tyson: I had a very poor experience with them last year.

Would help if you stated what questions you had so people could reply right away.I have knowledge on HELOANs but not direct experience.