My QRP-Labs QCX works well in WSPR beacon mode with the external GPS receiver unit. However, it has consistently generated a frequency drift reported by receivers. There has been some discussion on the QRP-Labs forum about this, and the FETs do get warm when the unit is transmitting.

I have been experimenting with my airspyHF+ for a couple of weeks now. It is a very nice device and I have been using gqrx on my linux laptop to view the entire 20m band, listen to QSOs, CW contacts and beacons. I've also used it to identify a few sources of strong QRM in my house.