Shielding has a lot to do with it from what I understand. FCC classes them according to how much RF interference they'll emit. Yet another reason you should NOT use commercial displays in people's home.
Extra chance of interference (including your remote control system), usually worse line scalers, usually worse black levels, etc...
Not all commercial models exibit worse performance in all aspects, but there's a reason why their cheaper than their residential counterparts - the more of the cost difference, the more stuff is pulled out and/or made cheaper for that commercial model.