For a minute there, I thought you had hurt yourself craning your neck all the time to look at the new setup ;-)
Seriously though....before you go through the trouble of mounting it that high, can I suggest the mock-up test and just looking at it for a short extended period of time.
And if you have little ones, pretend you're 2-3 feet shorter and imagine HOW much more uncomfortable it is. This is all very subjective.....and don't get me wrong, displays hung high look great *aesthetically* , but at 54" as a ref point of the bottom of the screen, it's really quite high.
You can pull it off somewhat if you have all reclining seats in your room......
Or if your watching from bed and need to see over your ice cream bowl and toes!