So for many years, I've been using Yodlee to aggregate my accounts. That is, it takes all of my bank accounts, credit card accounts, brokerage accounts, mortgages etc. and accumulates them into a real time single sheet of paper view of my net worth.
Then Prosper loans came along.
Yodlee deals with prosper loans very badly. Each of the loans is listed as a negative asset. That is, each loan that I own (money that people owe to me) is listed as a negative loan, like a mortgage in reverse. It is listed under debts. That is bad because it screws up how the asset and liability are calculated. It underestimates both assets and liabilities. Although the total net worth is the same, the components are wrong.
In addition, each of the loans is listed seperately, not in aggregate. This kills my ability to use yodlee as a daily overall asset watching device. Which is a pity, because this is the best web 2.0 application I know how to use. It is way, way better than Mint.