About half of my bikes have 2 speed kickbacks. The Bendix yellow band is very nice. Great brake and a good, clean shift. The Bendix red band seems like a slight step down. First gear is a bit rough on a lot of red bands I have ridden. Not sure if they don't hold up as well, or if all the red band hubs I have ridden were beat. I have also own a Sturmey-Archer S2C. This hub is as smooth as clockwork. The nice thing is, you can hear a "tick" with the shift, so it is fairly easy to figure out which gear you are in. The S-A hub is a substantially more sensitive than any Bendix hub I have ridden. It takes just a fairly small movement to shift. A benefit to the new S2C is the availability of several cogs. With the Bendix, you are a bit more limited.
Price wise, it is a bit hard. The Sturmey-Archer S2C can be had for $60 or so. Decent working Bendix hubs are a bit more expensive.
Rebuilding a Bendix can be pretty pricey. If any of you could recommend a good place to service Bendix hubs, I'd be grateful.