I don't use 4:3 at all on my widescreen.
top and bottom bars to get 16:9 on a 4:3 screen > side bars to get 4:3 on a 16:9 screen
It's just a bit of a strech to get a 4:3 on my widescreen, you almost don't notice it and get used to it within 1 min of watching it.