One thing I should add when comparing the MRX to Powerflarm: while the MRX detects traffic much earlier, the altitude difference can be very wrong nearly half the time. powerflarm on the other hand, when it detects traffic it always displays the correct altitude difference. So once the detection issue is fixed, it will be better than the MRX.
I am using the latest powerflarm version 2.4 and butterfly 3.0.

Ramy