Cutting round objects and metal or plastic extrusions in a miter saw presents serious problems of having the teeth of the saw blade dig in and either block the saw to a stand-still, or grab the piece and throw it to the ceiling. PVC pipe is great for exploding in the saw because it rotates into the blade.
It is counter intuitive but a saw blade with the teeth on backwards - or what is properly called a negative angle rake - can solve these problems. For details on the tooth design, see the video to the left on Tooth Technology.
Learning Curve 136