I have watched Spectro from several places and feel that watching from near the end of the route in the FrontierLand area is far better than the beginning of the route near the fire station / train station.
In the beginning, the CM's are trying to get the parade spacing down, therefore there are delays between floats. Once the parade gets on stage, there are a lot of good spots to see it from. I normally chose the end because the rides thin out during the parade and we can get in a couple before the parade makes Splash Mountain.