The main problem I see is people expect monks to do amazing DPR. Mine just specialises in manouvres, disarm, trip, dirty trick, reposition, steal, ki throw and simply shuts people down by making them prone, blind, disarmed and flanked. Then the 2 weapon fighting rogue, also supposedley a lower tier clas, simply unloads a full attack and everything dies. As for mobilty, cheap potion of fly, eventually a flying carpet or other flight granting options fix that problem.
Not saying it did not take some work to pull these tricks off, just it required a different way of looking at the characters effectiveness and build.