There is a slight difference in the thickness of the rail at the at the base and web, but not at the rail head. I've joined both makes without issue. My preference is for AtlasO as it will naturally form a smooth transition curve, while on fixed radius ones it it can be bent precisely to a radius line drawn on the roadbed. The other technique I use on curves to eliminate kinks is to stagger the rail joints around 4 inches so that there is at least one continuous rail throughout the curve. This is easily dome without cutting by sliding the rails in the tie strip. On tight curves I pull the rail, run it through a bender, and reinserted it in the Atlas tie strip.
One thing you can't easily do with AtlasO code 148 rail is use it for stock rail in conjunction with Lou Cross's (Right O Way) point castings. The "tits" on the outside edge of the point castings won't snuggle into the web of the thicker AtlasO rail without filing. I buy a supply of Lou's code 148 rail for making turnouts. It turns out ME uses Lou's rail in their flex track.
Ed Rappe
