Listing sandboxes is faster

GET /v1/sandboxes and every SDK's list answer a page about three times sooner in any account with more than one sandbox, and a list of only running sandboxes in an account with thousands of stopped ones answers in milliseconds where it read all of them. GET /v1/usage answers two to three times sooner in large accounts, and GET /v1/me no longer waits on a usage read. The answers are the same. See Sandboxes and Account.