Yes actually, I have played a monk all the way to level 20. I played my monk through every raid in game and even in epic content as well. What I listed are my impressions of the class in the 3 roles I have had mine in. During my several months as a monk in DDO I have built a dark path pure dps with no ac and all strength type, lesser reincarnated that into an all AC dex and wisdom build, and then lesser reincarnated that into a balanced build of both ac and dps. I spent time and effort gearing out each incarnation for each of the three roles I played my monk in. I then sat and watched multiple other classes outperform me in both aspects of the game for each of those roles. I watched capped barbarians run around with an epic sos critting for 700's every few seconds, I also watched intimitank paladins and fighters take no damage on raid bosses where as I could not come close to having decent AC vs raid trash mobs. They did this while making very few sacrifices for these abilities as well. Both sides outperformed the monk class with twice the hp as well as more damage or more ac, for equal or less effort then what the monk needs to put in, all while spending less action points and resources to do it.
This conclusion wasn't due to a lack of research either, I spent months on the forums reading and searching out different types of builds that could possibly do something useful with the class, I would acquire the gear all of the other forum posters would use, building for the stats and abilities other players recommended. Please don't assume this is a lack of game mechanics knowledge, exaggeration, or other fluff. I've been playing D&D since 2nd edition, and I have DM'ed 3rd edition for 10+ years. I know what class balance is when I see it, and I just don't see it here. Not to bring casters into the discussion but I also don't feel wizards and sorcerers are balanced either. Some classes have incredible major advantages over others in DDO without any reasonable or comparable disadvantages to make up for it.
If you don't believe I've done all of this with a monk, go myddo my character
Invalid on Cannith. I worked very hard trying to make something decent of the monk class or find some aspect in which it performed well in endgame content.
When that failed I went and true reincarnated my monk into a cleric.