DBRS isn't mincing any words: “Compared with other post-crisis representations and warranties frameworks, this transaction employs a relatively weak standard..."
Originators are constantly looking over their shoulders because loans are being re-underwritten two or three times, once by the aggregator, once by the GSEs...
The concept of MSR-backed securities recently came to the fore again with the news that Stonegate Mortgage, Indianapolis, is contemplating a transaction.