the difference beteween DCC and DC at my point of view..
Older models was DC and it was only in DC,most of railroad club was running in DC,wirering was simple,but,to run more than one train,it was required to separate track section on a certain lengh,add insulated rail joiner and add button to power or unpower a section,that was the way I working,all Atlas track and swtch,even,electric components for th "Y" and the yard..
Later,I discovered the PECO switches,that was much more easy and it was saving many wirering works,the switch blades was the contact point,price of locomotive was starting at 20$ in cheapest and was going to 60-70$ for a good one,I still go my very first locomotive I own,after 27 years,it still running very good,Athearn blue box F7 and it coast me only 21,99$ at this time,around 1989,my sceond unit was Athearn SD40-2,and I still have it and it's working great too,even if I reconverted my SD40-2 into DCC,it still good...
Then,sound appear on DC,with a main speaker under the layout and sometime,a bit more expensive and it was having a transformer that can have bell and horn button on it.
Then the DCC appear on the market,with sound system into the locomotive,instead to be in a main speaker under the layout..
Price was more higher,and the DCC only was also an intermediate option,for a bit less money.
Followed by DCC ready or DCC quick plug,to let the possibility to add decoder..
But again,an different controller was needed to run them separatly,no more need to insulate main track in many sections,each locomotive are now getting decoder with programmed address..Many of railroad club turned in DCC and now,single users are now using DCC for more fun and realist environment..
Just by looking on youtube,almost each model train video have been made with DCC materials..DC only model trains are not so much common by watching videos..I have my own layout that have two mainlines,one in DCC and the other are in DC and I got a pretty hudge collection of locomotives.That allowing me to run old model that I have not reconverted and run my brand new models,some very old material ae not easy to convert and I can run them only in DC.
And with somee friends,we made a micro railroad club and we do some show off,for the pleasure to share our passion with other peoples and the layout are in DCC..
When I make some videos of my model trains,it can have DC models ans DCC models doing meet on my layout..
Just by looking at the price of a decoder,around 25$ and I buying my new rolling stock,I have now the DCC ready option in almost every models I can buy..
By this way,I have choice to buy decoder now or wait a little bit before get a decoder,but I still can enjoy my new aquisitions right after purschase..