I have a KX1 and a KX2, both are great. However, for serious hiking and backpacking the extra weight of the KX2 may be significant. For a short activation that may not be a problem, but to me the power consumption especially on RX is an issue. With my KX1 I can operate for approximately 20 to 30 hours on the internal lithium batteries since I do lots of listening and I believe the current drain is less than 50 milliamps. But the one to two watts of power may not be enough for some folks, so the KX2 and other rigs with perhaps 5 or 10 watts of power may be a better solution. In the future I will choose whichever rig works best for a particular activity. The variable BW filter on the KX1 works "OK" but has its limitations. When set to a BW of about 700 Hz there is a nice peak in the signal at about 600 Hz, but strong signals on the opposite side of zero can sometimes be heard. Not a problem for me. Narrowing the filter further shifts the resonant frequency some, sometimes the result is not what one would suspect. Works OK at wider BW for casual shortwave BC stations and SSB. Never had a problem operating from many locations in the US and Europe with overload, but mostly operated with compromise antennas in remote areas. I consider the KX1 filter "satisfactory" for portable operation, and even some from the home station in my rural QTH. I even built a 15 meter rig and duplicated the same variable 3 crystal filter for my CW operation. I am a confirmed 99% CW operator for 67 years, but must admit that I have enjoyed a few SSB QSO's on my new KX2 on 17 meters.
Rick KL7CW