I have never had shift indicators until I got a mtb. And I never remembered to even use them since I wasn't used to 'em!
I just kinda glance back and down (between my legs, I guess) if I have any curiosity about which gear I'm in in back. But normally I go by feel, and with my bar-end shifters, by the position they are in (another nice advantage of barcons!)
Emily
2011 Jamis Dakar XC "Toto" - Selle Italia Ldy Gel Flow
2007 Trek Pilot 5.0 WSD "Gloria" - Selle Italia Diva Gel Flow
2004 Bike Friday Petite Pocket Crusoe - Selle Italia Diva Gel Flow