If you tried the Watson vision offering when it was "AlchemyVision" then you may have tried a now out-of-date version of the service. The AlchemyVision and Visual Recognition tiles on Bluemix have recently been combined in a way that utilizes their complementary strengths. Consider retrying the updated service if you'd like!
ok - my bad. I just saw the AlchemyVision has been merged into Visual Recognition starting May 20th. We will definitely check it out to see what extra features have been added.
qq - Is the API stabalized, by which I mean will there be further changes/merges?
Disclosure: I work at IBM Watson.