I'm 5'8''. My qh is 14'3'' (I dont' think she gonna be any taller). She's foundation qh, so no wander she's short. :) She has one of the most smooth trot I tried, and nice steady canter (and buck you off attitude too). Way much more comfy and smooth than my taller paint with really long legs or my neighbor's qh, who is 15'2''. So I don't think the height matters really, especially you are not huge yourself.
Personally, I liked both of them equally. :) May be try more riding w/t/c and on trails (to see how quiet/spooky they are). And also personality means a lot. In any case good luck! I think either choice will be great.