We love having the huge cabover berth. No kids in our rig but occasional guests who love sleeping up there. We enjoy occasionally using it for a TV lounge to watch a DVD as the 22" Vizio is on a swing out arm at the foot of the bunk (on the curbside). For us an entertainment center would be a huge waste of space and poor location to watch TV (which we rarely do).
The berth makes a great place to read or nap (or perhaps do a little better than nap), as well. :B Mostly it is a very convenient place to toss jackets, hats, odds and ends that are just an arms reach away. Another nice feature is that there are screened windows on both sides of the bunk with a vent hatch right over the middle. Since our 24' C has 7' of headroom the cabover is very roomy, not claustrophobic at all. Lastly, adding the entertainment center is expensive and for us totally unnecessary.
As always.... Opinions and YMMV.
:C