I love both fix gears and road bikes. I've settled on 5 bikes; 2 fix gear, 2 road and one that can do it all.
'08 TiCycles road bike
'73 Raleigh Competition set up as a gravel bike with racks
'83 Trek winter/rain/city fix gear - the workhorse
'11 TiCycles fix gear - the ultimate road fix gear. The fix gear that can go anywhere there is pavement.
'79 Peter Mooney - now a road, mountain and gravel fix gear though is has also serves as a road bike and toured
I sometimes get out the driveway, then think " I want to ride that bike, not this one" and go change it (and my shoes).
Ben