I think I like the bottom style if the room is really the media room. The top photo is more of a family/living room vibe IMO. You could do a mix of the two (depending on the wall length) and do the built in cabinets below the TV and skip the shelving.

I don't think either way is wrong. Just personal preference.

Hi. From you description, this sounds more like a small movie theater. Either way, I recommend no built-ins. As you observed, the built-ins are, in my opinion, just something else to decorate and add clutter.

Consider also, that tv's change. They started out as small boxes, After that, larger boxes and were put in large entertainment centers. Then, flat screen. So, good bye entertainment centers. Now, flat screen hung on walls and tv's are getting larger. So, by adding built-ins, you are limiting yourself for the future.

What will tv's be in the future? We don't know. Some have gone to no tv and just use personal devices.

I also recommend you look at the 2 photos above. Which appeals to you more personally and which goes more with the style you want in the space?