There was some discussion a while back as to whether or not the mouse eared pulley was designed to support the directional forces if used as a hitchclimber-like pulley. It appears to be strong enough, don't know if there was any definitive conclusion there.
The deal with the Hitchclimber is that it was specifically designed for the purpose and can be loaded any direction in any configuration using any of the three holes. Worth the additional $30 bucks. It is very compact, I've only seen pro climbers use it, they love it 100%. But... the climber makes the gear, not the other way around. Absolutely must have an eyesplice on one end of the climbing rope, as I mentioned before, a knot attachment to the biner in the top hole will contact the hitch and prevent it from seating on the down rope at the wrong moment. That disqualifies me from using it, I don't like spliced eye's on my climbing rope, makes it difficult to put my favorite pipe style cambium saver's on the rope. Too many limitations start to happen, I want to be able to take pipes on and off the rope at either end of the rope at any time during a climb.
-moss