As far as I can tell, MorphToken doesn't allow you to set a fixed destination amount. In other words, when going XMR->BTC you can't set or know the exact amount of BTC that will be delivered.
ChangeNOW allows that, but has a much higher minimum, .003 BTC or so. Not useful for small transactions.
And all of these services take many minutes to complete the exchange, by which time the invoice you're paying might expire. AFAIK xmr.to was the only one that did instant exchange with zero confirmations for smaller amounts.
