If this sounds like it's coming from a n00b, then since I've only been playing since a couple of weeks before Cata...
I've looked quite a bit, and while there is plenty of BiS analysis available... there's precious little analysis I can find for "best that I can afford" / "even then is it worth it, or should I wait".
I currently have heroic left eye/normal right eye. I have enough tokens to buy riddle/stump... I am a long way of having enough valor for anything... and am not spell hit capped (~1300 or so, and am draenei).
1600 agi is, of course, a lot. However given it's uptime (if I hit it perfectly every time, which some fights might be difficult to do) it equates to 400 average... is this worth more than 321 hit when it would get me within inches of spell hit cap? We also seem to cast a lot, especially free spells, so what's the % proc on stump, and does that push it over?
Or should I hold off on either, get a pretty mount in another week or so, and look elsewhere for a trinket (like I said, little valor, and hard to get into the raids to get gear with a 333 in my second trinket slot :P)