I'm afraid that it's all lost on me.
I've moved to O scale because it's the scratch builders' scale. I can understand buying ready made electronic bits to save time and expense, but we are modellers - not collectors - or are we?
The people who can produce attractive paint jobs are just like us. Two hands and two eyes - in most cases. 
They did poor work when they started out, but they persevered and got better and better. So can we.
Having said that, I now remember the days of building block detectors and the like, so electronics is in as well. 
Basically, we can make anything we want - just have a look at JPV building his 3D printed rolling stock.
I reckon that if you buy it, you're a collector; if you make it, you're a modeller. 
. . . and it works out a lot cheaper. 
