Well like many we go with great expectations but alas we often cum up short. Its great when you get a girl who loves to blow or please a man with this technique.
I think your favoured position also has something to do with the feeling of power and the relaxed position where you are master of all you survey.
Deep throating is also a needle in haystack experience so well done to the girl. My experience is that only happens on Pornhub or other sites.
I hope you weren't a Scrooge and rewarded her well, this sort of service needs to be encouraged. Lucky bugger!
4FoW2