Good discussion! My first exposure to SCHRS came with involvement in the Florida 300. I'm impressed with the math and analysis they use to arrive at the ratings.
The biggest roadblock I see to using it widely for local regattas in the USA (besides inertia - "we've always done it this way") is the nature of the bulk of racers at popular regattas (casual and have customized their boat in some way).
The way we do it for the Florida 300 is to use the ratings from the SHCRS ratings table http://www.schrs.com/ratings.php
for a boat IF
The skipper can certify that their boat is a factory stock version of the rated boat, otherwise they need to get an individual SCHRS certificate.
If someone shows up to race with a slightly modified boat and no SCHRS certificate then the PRO will assign a rating.