It all depends on whether you need it now or whether you can wait. If you wait, you may be waiting for specifications that never materialize. Generally it is better to act on what you actually know and not what might be, so if the M5 machines meet your requirements I would go ahead and make the move now rather than wait for an unknown period of time, for an unknown specification and an unknown cost. It all like the saying “A bird in the hand etc…”.