Yeah, slingers by themselves suck, although if you can camp in a city it's not long to the +10 promotion, at which point they actually are fairly strong at fighting barbs who are sieging your city, especially since they can take shots at them without hurting themselves. And then obviously once archers come online, they can really clean up.
I'd love to go builder-settler, or scout-builder-settler, or even scout-settler, but especially since the recent updates, I find barbarians are just too deadly, and my warrior is woefully horrible at spotting where the nearby barb camps are. And because of that, I'm pretty much always forced to get a slinger in my first or second build (lately I tend to do scout-slinger-builder-settler, although that does make for a fairly slow 2nd city, unfortunately).