In my opinion and experience snow foaming isn't a must have. The theory is sound but in reality if your into your car and detailing, it won't get dirty enough for it to make a difference if your jet washing your car first anyway.
I'm very glad I didn't spend £40+ on one, got a cheap one of Amazon for £15.00 and it works just fine and the Bilt hamber foam I use doesn't foam up that much anyway.
Benefits - it allows you to get the foam in the wheel wells and it looks great lol
My plan is to use it instead of a wash bucket. Going to add some soap to the mix of foam for extra lubrication and spray car.
Then have a bucket of plain water for rinsing with 2 mitts to wash the car with, 1 for the top and bonnet and one for the sides and bottom.