I?m using a GRT sport Sx Efis. They use the sl30 protocol for the Val Nav with sucesss so I am hoping it will also work with this radio for VOR/LOC/ILS feed to the HSI and needles on the PFD.
I like the small 2 1/4 control head of the Vega. Combined with the Garmin GPS 175 should be winner for ILS/GPS approaches.