if it bugs you get a screen with additional drop.
but if i were you, i'd break out a bed sheet or something and actually try it out. it'll kind of depend on your seating as well. we have some recliners, having the screen as high as possible made viewing way more comfortable. i WISH i had the problem of 10ft ceilings, haha.
at the end of the day, you gotta do what feels best in your room, not what some 'guide' says is a good idea in a perfect world
Displays: Samsung PN64F8500/JVC X35
AVR: Pioneer VSX-1018AH, 5.1 audio
Sources: HTPC(Mediabrowser), PS3, XBOX360, Wii, Sony DVP-CX995V
Control: Harmony One