I think it should be possible, but I've still got nightmares about what happened before with upgrading from 7.1.x to 7.1.x.
The last upgrade from 7.1.5 to 7.1.6 went successfull though. No problems whatsoever.
But I'm still hesitating if it is the right time to upgrade from 7.1.6 to 7.5.1 or wait until a later vesion has been released.