Do either of you wear glasses? Consider the "sweet spot" in your lenses where you will be watching the TV. If you're like me, you will unconsciously adjust the angle of your neck to focus on the screen. This can get uncomfortable after a while.
I have a 37" Mitsubishi sitting on the credenza
in my 34' Excella and sit across from it in a Lane recliner
about six feet away. Eye level for me is about even with the top of the recliner. You can get an idea of the relationship from the photos in the links.
I also use it as a monitor. The bottom third of the screen is about eye level, so I find myself positioning things I am working on in that area when I can. I will admit that I have no problem when viewing TV, but I would not want it any higher.