iOS doesn't use Alex, no. A regrettable decision, but perhaps not so surprising because Apple voices are not multilingual.
In my opinion, in very basic comparative tests, Alex is right up there. I would, of course, prefer the option of a completely rules-based formant engine on OS X, but let's just say that the first page of "Ground Zero" from ChooseYourStory.com reads correctly with Alex, right down to the apostrophes in the tensations.
@mikerschs2: I'm afraid you'll have to buy that Mac. The Mac Mini is cheap nowadays; go there. Or, perhaps, if you just want samples of text converted, you could let one of us know and we could do it for you.
Just myself, as usual.