To be honest, I don't really have a preferred TV height for the new room. It's a totally new experience for us, as we've only ever used a 35" 1080p TV that came free from our internet provider, which is currently sitting on a low IKEA entertainment unit. We didn't even need a sofa with head support, as the center of the TV is quite low to the ground.
I have come across some suggestions online that state the ideal height for the center of the TV is 3.5 feet above ground level, but after experiencing my brother-in-law's 65" TV, which was mounted four feet above the ground level, I found it to be quite comfortable with a low-backed sofa. But then, I also recently stayed at a hotel with a smaller TV mounted high on the wall, with the center of the TV about 63 inches (5 ft 3 inches) above ground level, and watching it from an armchair without head support was also quite comfortable. (Although that was only for a short time and that TV was clearly meant to be viewed from a bed).
So I'm basically still trying to figure that part out; do you have any recommendations on where to mount them based on your experience? Thanks!