Tried it and had the same issues, primarily lack of rage and a huge drop in TPS, (1-1.2k if omen was accurate). Given a fair part of our threat being procs (Revenge /S&B) I assume this was whether the threat had gone along with being stingier on HS/Cleave.
Last laugh dropped the following week which made it academic on what to use when tanking. However I've dug it out of the bank when I got another lollipop to have a play around with dual wield tanking again. Unless there's enough rage around to justify its use, given the way 51 points in prot works out.
Former TBC/LK Tank
Waiting for Dunmail Jnr to sleep to enable online gaming.