Of all the rigs I have ever owned, I believe I like this one the best. But I replaced them with higher-rated ones and soldiered on with no more problems. My Swan CX was a pretty good radio and it drifted very little. However, during the QSO, when switching between Tx and Rx using the push-button switch, the receiver would drift, requiring constant touch-up of the tuning which is an RIT or regeneration which also varies the Rx frequency. The transmitter had a very nice note with only a little bit of chirp. Normally, all you have to do is ask.
It has the best noise blanker I ever tried.
One-Tube Transceiver HF-19
A noise limiter was not included and an optional crystal calibrator was available. At least not after I found and bought the external VFO. A spare electronic tube for Collins 51s The one on my IC Pro is useless. I do not believe the article suggests a Swan is superior to Heathkits.