Yup in the media room didn't do split boxes. I did utilize split boxes for the on the wall LCD TV's in some of the rooms. I did start with all Arlington boxes originally; well constructed. Most difficult was doing the laundry room; but redid everything in there anyways (new floor, shelves, lighting). Figured I might as well add the TV to the mix.
I did add more electric and more in wall boxes in the family room sort of dividing up the boxes and using 6-8 keystone jack plates. It was very tight. IE: one keystone plate has some 8 catXX cables going to the patch panel. I put speaker terminals on another one. Also used tiny labels that I can't really see well unless I am right in front of the keystone jack. For the in-house, satellite (did the two DTVs connectivity), cable and OTA TV stuff went to that thin RG-6 cable in the wall to the wall plate as it was more flexible and very thin. I did not see any changes in reception. It was a bit more expensive though. I purchased short 1 foot cables; very thin stuff and aesthetically pleasing. (to me as I do not think the wife noticed or notices the cabling). I did also do a whole thing related to the powered subwoofer that is more of a piece of furniture in the back of the room with its own LV / HV separate stuff. You don't really notice the speaker; just hear it really.