Hi johnboy45, welcome to the forum.
Absolutely loads of planning appeals are lodged on the grounds of "loss of privacy", "loss of sunlight", "overshadowing", "loss of amenity", "de-valuing of property" etc. People object to everything and anything these days.
Usually in an attempt to hide the often pathetic, nimby reasons behind an appeal, the objector will be advised to play the "it's out of character with the surrounding area" card. It just sounds more plausible.
As for the cul de sac, not being familiar with the case I couldnt really comment but the obvious one's there are, impact of increased traffic levels, suitability of road network, access points etc.
Im sure you'll find plenty of info about planning appeals on the City Council or An Bord Pleanala sites.