I regularly try making APRS QSOs with my TH-D72 and a yagi, and I'm occasionally successful. I find the ARISS digipeater is difficult to get into with that setup. I'm not sure if it's an equipment issue or if the station blocks the antenna somehow. Hopefully they get the upgraded system going soon. The automatic beacon stations also don't help, since they just cause collisions. I put "live" in my beacon message so ops know they can try to QSO with me. PSAT is easier, but the APRS is barely ever on. Falconsat seems more reliable, but with fewer operators on it. Finally, I've found even terrestrial APRS to require more power than FM voice in order to work reliably.

-Stephen, N8URE