Welcome to the Lego train hobby! This is the way it starts BTW. Pretty soon you'll have all the currently offered trains and start looking longingly at the vintage sets. Before you know it you'll have the RC trains, both Santa Fe sets and the Metroliner. This leads to the My Own Train series and various add-ons like stations, freight depots and rolling stock MOC's. It's all a blast!
I recommend you take the PF gear out of the passenger trains and get the Emerald Night before it's too late. PF the Emerald and you'll be blown away by it's beauty. The passenger train on a depot siding still looks great even if unpowered.
Again welcome to the Lego train obsession