I was kind of on the fence between the 65 and 75. The 65 was a perfect fit but I am kind of thinking now, a year later I could have squeezed a 75 in, Im still very happy with it, dont misunderstand me ... *L* Anyway, the X900H is an awesome display, the contrast and black levels almost look 3D which I am sure you noticed by now?
In this room we have 16 foot ceilings and six large windows all the way up with no blinds or window treatments, they are tinted with 3M night vision treatment, anyway, during the daytime the picture doesnt get washed out even with the sun shining in, not ideal but doesnt get washed out.
You can see by the photo why I was torn between a 65 and 75. The 65 fits perfectly but I think now, a 70 or 75 would have too. You can see in the reflection on the screen there is a fireplace on the other side of the room that would be perfect but we dont like fireplace mounted TVs. Feels like a compromise mounting it in that way.