i was looking at the AIO's recently and actually
wanted the touch screen, that system would be primarily used by mom and dad (dads 71) and honestly it would be so darn much easier for them. ive tried and tried to teach them the proper clicks to open programs. i gave up on that, basically settled on a launch bar app at the top of the screen with the things they use most up there. one click and done. unless of course they get a "yxz wants to update" pop up, then i hear the inevitable call to help.
now me personally, ive used a "touch pad" to try out some of the win8 gestures, and honestly didnt see the appeal. not having folders on win8 start drives me bonkers. but, this OP is about the hardware, so let me get back to that.
why does it need to be an AIO? unless im wrong ive all ways assumed theyd be a PITA to work on, or find parts for other than proprietary. so why not go with miniATX and a "cube" case? depending on your needs you could "sort of" make it an AIO visual wise. or get a case thats easy to mount under the desk out of the way and just have monitor/speakers up top. ive actually been trying to find a monitor with attatched speakers or that they could be attached to (remember when CRT's had key hole slots for speakers? man i miss that) so i could have monitor/speakers mounted on an adjustable arm so i could adjust display angle/height depending on what im doing (im legally blind, i can only focus on one part of the screen at a time, some times it makes more since to move the screen rather than the program)
currently i have an xps 8700 that ive had no end of over heating problems with, i sort of think its the i7-4770, ive seen a few "delidding" charts and think that may be the root cause in my case (even using a copper core heat sink and taking off side panels havent helped the lil volcano)
edit: managed to tab my way to post now some how, sorry, i was going to say, so my next build will probably be a mini tower with water cooling, or a mega ultra holy cow that things huge, tower with water cooling. not sure which one yet.