And no, it doesn't make designing API easier if you preallocate "read", "create", and "delete" operations to separate HTTP methods, and then put all the other operations in POST. "Create" and "delete" in many cases don't even make any sense to guarantee their being specially distinguished.
And you say that RPC can be used under REST. Do you have any example of a REST client library that actually can do that? It's the first time I ever hear about this way. Almost everybody else uses REST like an underspecified RPC protocol, cramming call request into an ad-hoc JSON structure to HTTP POST and mixing error reporting from transport layer and from application.