tynaskos posted:I will swap out some of my 72s for the 7.5s.
Swapping out O-72s for #7.5 switches is an entirely different issue than what is the difference between #5 and #7.5 switches. AtlasO #5 switches are somewhat equivalent to an O-100 switch, making the #5s much better operationally and aesthetically than an O-72. Replacing O-72s with #5s for a crossover greatly lessons the S curve effect.
If you have room for #7.5s that is great. But #5s are plenty good for 3-rail operations and are cheaper. And as Hot Water stated, the rail gaps in #7.5 switches may cause some of your engines to stop. This is less likely with a #5.