This same topic comes up every 2 to 3 months....for me....Gargraves and ROSS. Layout size is 25'x35'. I have been using this combination for a LONG time. Back in the day it was Curtis switches and Gargraves. Ease of construction with the Gargraves and bullet proof design and construction of the ROSS. If a switch ever breaks, Steve will take care of it for you. I doubt you will find that level of service from Atlas.
I have some Atlas 40" rigid that I use and also have (3) Atlas bridges with their track. I make my own transition rail joiners to mate the Atlas to Gargraves.
Just my opinion.
Donald