Remember that this thread has been about Tomas' proposal, which might be merged with Beman's library or might be proposed as an alternative. The current interface isn't critical to that discussion.
Which is why I've effectively withdrawn from the discussion now, as this thread was hijacked.
I'm trying to accommodate the discussion, in this and related threads, in which many of us noted the inefficiency of the arithmetic operators and hence the need for something like Beman's boost::endian without those operators.
Code which encourages bad coding habits/inefficient code shouldn't be in boost, full stop. Having the arithmetic operators on endian types is a completely wrong separation of concerns - it's akin to throwing away types and writing all code just using void pointers. I don't see how Vincente fails to see this.