Even without understanding the reason which it takes to Creative to put a loudspeaker, which I doubt much of its quality of audio, in a as small reproducer as it is the Creative Zen Stone, it does not seem that it affects much to a comrpador of this type of reproducers.
When you buy a reproducer of this type, so small, with an almost nonexistent screen that shows the basic thing, I do not believe that what you look for is concretely power in a loudspeaker, to if that why? The new models of Zen Stone and Zen Stone Extra loudspeaker has this micro, will come in capacities of 1 and 2GB in the case of the Zen stone, in the Zen Stone Extra the capacities are of 2GB and 4GB.
Buy from Amazon - Sony Mylo 2
Buy from Amazon - Archos 605 Wi-Fi 160 GB
Buy from Amazon - Creative Zen 16 GB (Black)
Buy from Amazon - Zune 80GB (Black)