I'd still stick to the 789, used it can be had pretty decently priced. If you want shoot me a PM I've got a great condition one and an SU-8 I could part with.
I just realized the dx3 pro I have is 10 ohm output resistance. Not the measured 1 ohm from v1. So it is going back since I primarily drive low ohm headphones so far.
I actually might keep it as the DAC. Depending on what replaces it for amp.