From what I've read so far this really isn't the trinket for ret, besides the fact that its just a bother to have another CD to have to track and doesnt mesh with our other cd's, you have to crit to build stacks which seems to be a mechanic better taken advantage of by classes with duel wielding or fast attack speeds. we unfortunately have neither.
I know its tempting to pick this trinket up because it's easily accessible on the AH or from a trash run, but depending on the trinkets your wielding now, you might be better off waiting for vessel of acceleration and the rep trinket.