I've got the 02 at the moment which I think is called the comfort snaffle. What is the difference between this and the 32? I think they are both dressage legal and I was thinking of getting one with full cheeks.
Yes they are both legal. The 02 is a level 1 whereas the 32 is a level 2. According to myler that means the 32 will work more on the bars than the tongue (the 02 is more tongue than bar pressure). Full cheek is fine so lomg as it doesn't have hooks (the holes in the bottom of the ring for your reins). I use a hanging cheek 02 and Horse really likes it.
So long as you bought the dressage legal version of the comfort snaffle. My myler is a comfort snaffle but it does have the copper inlays, I'm sure you have to specifically buy it wihtout the inlays to make it dressage legal.
Copper inlays are fine for dressage.
The MB32 is a mullen mouth piece, it still has the independant side movement though.
The MB02 is more flexible than the MB32,
there is also a french link MB10 which is also dressage legal