I would just use combs on longhair cats - get a fine-toothed one and a second one with medium/wide teeth. I have one comb that has half as medium width, half as wider spaced. But you really should have one fine-toothed comb cause that really does the best job after all mats/tangles are out
My cat has a ridiculous amount of hair, and if I don't comb it regularly enough she gets dreadlocks and I have to cut them out!
But when I am being good and combing her regularly, I just use a simple little black hair comb made by Goody. I'm talking about the kind you can get for about a dollar at a drug store. I get the ones that are fine-tooth on one side with bigger, wider spaced teeth on the other side.
It works great! I have tried fancy expensive cat combs from Petsmart and whatnot, and they don't work at all compared to this.