I haven't talked to anybody yet, so I can't say whether their customer service is something they could work on. They are definitely selling a product and some salespeople are more aggressive than others or better trained and capable of doing their job than others. I think what we have to worry about are the terms in which they get these 0% line of credits, the time span for those lines of credits (LOC), whether their 60 day money back is legit or not. They have lots of good reviews, but you never know. I'm also skeptical of paying for a service that I haven't received or that would take place in the future, so finding out about their money back warranty would be something to get to.
I can understand their 9-16% interest rate after the 12 months 0% promotion. People get this LOC all the time with their personal credit cards and after the 0% promotional period it goes to the regular variable rate their credit card may have. Apparently they have the ability to get much larger LOC than someone could do by doing it on your own and that's where the premium has to be paid.
I see them as a good opportunity for fix/flip and buying houses where you can implement the BRRRR strategy. It has to be something where you are in and out in less than a year so you can pay back that LOC and take advantage of the 0% interest. I believe the money has to be used very diligently and with a purpose. Otherwise is a teaser to get yourself into a lot of debt and lots of problems.