I also had Alta and Sur-Ron. But sold the LBX to buy a second Alta for my son. Fortunately, the Sur-Ron has a robust resale value, especially now that you can't get very many new ones from China.
I did test ride the KTM around the parking lot. It was certainly fun, just not "Alta fun." (Plus, it was twice as expensive as the used Alta I picked up, and I couldn't order a second battery for it.) Easy choice.