It probably doesn't matter. I was never able to get my dog to cooperate when it comes to brushing teeth so I just give her something to chew on like a nylabone or rawhide. Chewing on something like that probably works better at removing plaque then brushing.
i use a soft toothbrush *i have a med soft one if she gets stains* and i use baking soda. just have a baggy of it and i get the brush wet and stick the bristles into the soda. it works really well and while her breath isn't minty it doesn't smell bad.
I think the enzymatic ones are preferable (do they all have enzymes?). I got some at the vet for my cats but I think you can get it online, too -- the C.E.T. brand.
My dog is still young and doesn't have any plaque. I honestly wonder if the digestive enzyme supplements he gets (not for his teeth!) help -- his teeth are gorgeous -- or if it's just age (he's coming up on 1.5 years).