Just my personal view, the ground level trackage looked far better, and was visually far more satisfying. However, back and knees no doubt favor the elevated railway, and unless you have enough space to create a gentle grade up to an elevated steam-up station, ground level is tough for oldsters like me. That being said, I'm still building on the ground, on some fairly good-sized sections of fill locally, but only gaining several inches over just being flat on the ground. I will of necessity be having an elevated steam-up station to accommodate my physical limitations, but I suspect that there will be many times when back and knee issues will have to be suffered to keep on having "fun"!?!?
Whichever way you are doing it, beats not doing it by miles!!!