From my personal experience..SS/FG is the most reliable and troublefree set up... However you do need to be in a very good physical shape to ride one. I have 3 bikes and I run them SS or FG. When I started out few years ago I used a deraileur for my first winter, I had to keep my drivetrain very oily and greasy to prevent it from freezing.
I don't plan on going back to gears, I use SS/FG all year round for all types of riding.
One thing to keep in mind.. I did wear out a 9 speed cassette and a triple chainring set up in just one year, but I have never yet worn out a track cog, or a SS freewheel or a SS chainring, they last so much longer.