Sometimes, pictures work just as well as words, and since I'm feeling a bit lazy today, I'll use them instead of having to put thought into type. So here are a few pictures of the Mad Alchemist's Potion in action on the PTR. Enjoy. =)
Notice the actual description of it's use? The potion only gives a chance of a side-effect buff, not applying one with every single use. Given what Drysc had to say earlier, this is incredibly disappointing, because it sounded like the potion would proc an elixir buff every time. Instead, we are left to wonder not only what buff it will proc, but whether or not one will be applied at all. And after a bit of testing, the proc rate seems to be low, on the order of 1 out of every 10 uses or less (not a single one out of ten procced for me during testing).
Now keep in mind, all of this testing was done on the PTR and and may not be working as intended. But as things stand now, this is definitely not the buff to Alchemy I once thought it to be. Hopefully things will be tweaked for the better once 2.3 goes Live, but in the meantime, we'll just have to wait and see.