I wouldn't really call it a shimmer...more a light sheen. Try it at the counter and see if you can pull it off! The lighting isn't going to get any worse than at a counter hehe. Sheertone shimmers are very buildable as well (esp with a 187 brush) so you can go easy with them if you like
i agree with kat. they're really bulidible (sp?) so you can make it as heavy or as light as you want it too. and its def. not glittery like you think it gives you a really nice glow. but the best way to find out is like kat said try it out over there.
My Mom (late 50's) uses Springsheen all the time now (she stole mine, the rotter). Gives her a healthy glow.
I'd say as long as you use a light hand, they are good for any age.