I have a lot (>20) of Atlas #5 and #7 turnouts on my small layout. I found two consistent problems with Atlas turnouts:
The first, which I found to be more prevalent on the #7 turnouts, is insufficient curvature of the curved point rail (that for the diverging route), which narrows the track gauge, causing wheels to bind due to friction. A little careful bending can solve this problem.
The second, the spacing of the check rails and wing rails for either route can be too great... you can check this with an NMRA track gauge. As the wheel set passes thru the turnout, distance between the back sides of the wheels is narrower than the distance between the check rail and wing rail, causing the rails to either grab the backs of the wheels, or forcing the wheel set up and derailing it. This problem can be remedied by carefully heating the check rail with a soldering iron and moving it over a little with fine pliers or forceps, and then re-checking with an NMRA track gauge. You need to work carefully... the check rails are held in place by two metal pegs that stick into holes in the plastic ties... if you move too much and the holes get too big, the check rail will be loose, or come out entirely. Fortunately, easily glued back in place with super glue...
AFter making these adjustments to many of my turnouts, AND properly gauging all my wheelsets, I rarely have any turnout issues... Good Luck!
