I use 10ft rods mainly because all the swims i want to fish are overgrown and have over hanging trees,it does make a difference to me as the margins are deep and my 12 foot spomb seems to catch on the trees behind,
given the choice and the space, I think I would use a 12 foot rod, but the 10 footers do a good job and have performed well in tight situations for me this year, although I don't need to hit the horizon,for that I would definately prefer a 12 foot or longer rod