Grooming clippers

Question
I have a Maltese, Bichon Shitzu and a Terrier cross.  I bought a medium duty Oster clippers which I was told was good enough for these dogs.  The clippers hardly touched the hair.  I was checking out and Andis #22185, model MBG2 on the internet.  The reviews claim it's very good.  What kind of clippers do you use or recommend?

Answer
Ginny,
You have a hairy dog- forget all the titles.
Reviews are only worth anything if you can use the equipment. You need more than clippers to groom this dog.
I have been using the single, 2 speed Oster A5 and turbo clippers for 22 years, also have a pair of Andis which are not much different so far as I am concerned- it's who is using the equipment that makes the difference. I don't buy equipment at big box stores or discount pet centers but only from professional catalogues and dealers.
I went to school to learn how to use this equipment but if you are determined to learn there are videos and books you can buy to give you the information you need to learn. I don't know what a "medium" duty model is but it sounds to me like you don't know how to use these clippers so why are you going to spend more money? Have you combed the dog free of knots and matts? What number blade are you using? That is usually the reason a blade does not go through the coat.
If you can't run a metal comb through your dogs coat with it catching you won't get a lot of clippers through it either if it is not a pro model. The coat needs to be fully brushed out unless you are stripping it to the skin and you  need to be very careful doing that or you could cut and or burn the skin.
hope this gets you on the right track.
good luck.