I think Greg's answer which bounces a lot of the issues back to you makes a lot of sense. In addition to that, you said aesthetic reasons were important to you. Are you a rivet counter? I am not. Atlas track and a combination of Ross and Atlas switches work fine for me. I do NOT ballast the track. It's not worth it to me.
I recall reading some time ago about someone who used electric cable ties to secure track. I assume 2 ties to hold it in place. The cable ties simply hold the track in place. They do not secure it rigidly to the plywood, so the sound is not amplified. I have NOT done this. But it makes sense to me, and maybe on the next layout....
Gerry