Just as with the table saw, a good blade makes a world of difference on a miter saw. Even though miter saw cuts aren't quite as long as those made by table saws, miter saw blades have a unique set of demands made on them.
With a table saw, the wood meets the blade at a low angle and is then fed past it. Miter saws, however, operate by dipping downward. Though they can also start at one end of the piece of lumber and cut laterally through it, they must occasionally break through the wood by being lowered directly onto it. This process creates a whole new degree of strain on the motor, particularly since the tool is largely used for denser crosscuts.
The blade that comes standard on the majority of miter saws has around 24-40 teeth and is best for rough cuts, like those on dimensional lumber and deck material. This blade does not make a very clean cut and or handle well in hardwood. Since the miter is so often used for crosscutting, it makes sense to upgrade to a higher-quality saw blade.