I was wondering what the prevailing wisdom was on mixing the two in the same layout. From what i understand atlas has something called a transitional rail joiner thant takes from one height to the other. Reason, i'm not so good w/ laying track yet, but i need larger radius curves to run my trains and rolling stock. Code 100 has 22" and code 83 has 24" snap track which would make parallel tracks easier for me to layout. I've search and searched and i can't find 24" radius turns in code 100 which is the entirety of the track i currently own.