I think it will be very tough to find that balance for both investors and individuals trying to take a loan. On one side if you want a loan will a person be willing to put up their BTC but only receive 20 or 30% of the value of it in US Dollars....... It might not be worth risking it for so little cash.
For the investors they are trying to loan on quicksand and could end up upside down in a matter of weeks. So Imagine this. Let's say they did give 50% LTV and then Bitcoin drops 70%. Well the borrower could just not make their payment and let the lender "foreclose" on their Bitcoin and the borrower would have the USD to just go and buy another Bitcoin at a lower price.
From what I understand SALT is mainly a 3rd party bringing the borrowers and lenders together so they aren't really taking on the risk. It is the accredited investors who are taking on the risk. And if you think about it most accredited investors are older and would likely not want to have something so volatile be the collateral.
I'm sure they must have some safeguards in place for this but what's to stop people from taking loans and just walking away with a 70% profit? It happens on Lending Club and Prosper I see the same thing happening here. Maybe once you burn the community your out but your still up 70%.
That is what I figure. A reputation system like on eBay or Amazon but if you cut and run you just burnt that situation out for the short term gain!