Agree, there's always debate about snow foam, much like the manual v DSG debate
I don't think anyone really thinks that snow foam is some magic potion that will transform the car on it's own, it just one possible step in the process. I have used Auto Finesse Citrus pre wash a few times but never felt it gave as a good a result as snow foaming. It does very much depend on the foam imo, there are some poor ones out there that do little more than coat the car, but a good foam like Valet Pro Advanced Neutral or Bilt Hamber Auto Foam can make a difference and give good results. Those that use snow foam just because it's fun and looks cool are kind of missing the point.
If you're going to do it properly, snow foam can be an expensive option initially especially if you need to buy a pressure washer as well as a lance, but once you've got the equipment then it's just the cost of the foam thereafter.
As with most things it's down to personal preference. At least there is a choice with lots of pre-wash solutions on the market too.