I've just flashed a TM-AC1900 into an RT-AC68 and I'm setting up 378.51 on it.
Quick question regarding the USB 3.0 port: I've got an USB 3.0 flash drive that I'd like to use for additional storage/Entware/etc. Are there still interference issues these days between using USB 3.0 storage and the 2.4GHz band or has that been a thing of the past with recent version firmware?
I believe that this is still an issue with the RT-AC68U/R, but not so much with the RT-AC68P. So it depends on which model you have.