Hallo Paul
about 3 years ago I was faced with the same decision… KX2 or KX3
For me it was the KX2
I don’t need a 160m band for SOTA.
It has almost the same performance (also the tuner)
It is much smaller and lighter (and cheaper)
I do not need the other functions
Yes, I also like to do 2m SSB. But then it is a deliberate activation and I take a 2m antenna and the transverter with me. The transverter is very light.
https://reflector.sota.org.uk/t/how-to-activate-2m-ssb-with-low-budget/21150
If you start a search for a KX2 here, you will find many useful tips.
73 Armin