I used my SS for most of the summer, mainly because I use it to go the my lady's house and we go down to the beach together, 10 blocks of steep hills, too lazy to spin down the hills...so I just coast down with her. I'm used to the hills...I live on one but I like to coast down with her because we can chit chat along the way and not just drop her and leave her hanging.
I think SS/fixed is useless for the experienced fixed riders, seeing that they will probably never use the singlespeed side again. I kind of wish I have a double fixed though.