Carl - More of a subway-surface guy (rode that more than the El). The Market Street El has been redone and looks nothing like it used to (same for the Frankford El). The elevated on Joe's layout was an afterthought. Had to integrate it into existing space (including track spacing) that wasn't planned. Plus, he wanted to use his Real-Trax.
Read most of Lee Willis' Super-Street posts. Downloaded his book linked from the forum. Don't know if we'll integrate streets or modify as much as he did. We'll just lay the buildings out and take it from there. May use connectors on the building leads so the buildings could be removed later if necessary.