It (R/C) also works inside, particularly if you hate wiring like I do.
RC works (most of the time), even if you like or love wiring. There is not too much wiring on little Gn15 layouts.
The main advantage is, you don´t have to spent your time with track cleaning anymore, if you have batteries on board.
For live steam in the garden RC makes sense. You have to be on the throttle all of the time to run them through curves or up and downhill. Still most live steamers run much too fast.
A Smallbrook Nellie propbably needs a tender for batteries and receiver. The resin castings are very solid.