I'm a big proponent of Beltline Rail. I am not a proponent of the existing streetcar line downtown. I think the CoA set transit back with that project. Transit without dedicated lanes or ROW is destined to fail.
Trackless trams and busses along the Beltline are not a good solution or alternative to a streetcar along the corridor. Here's a video on the pitfalls of Trackless Trams:
https://www.youtube.com/watch?v=RjKG0Lw1uFc
As for the Piedmont Park trail, what's different for the path in the park that just opened vs what was there already? It looks like the simply added a marker down the center of the path that was pre-existing? Or was it widened and/or lighting added? (I can't remember if that was there already)