I've found Lutherans (and Catholics) to be the most intellectually committed Christians and often pretty laid-back in comparison with mainstream evangelical Christians... I've never had a Lutheran get up in my face about their religion (maybe because most of them are Scandinavian in background?)
Then again I am from Seattle and most people there are laid-back in general.
But yeah I was confirmed in an ELCA and only know other ELCA's, but we never had to sign cards or anything. I enjoyed going up as a group to kneel and receive communion; it was a time of introspection and humility while waiting for the eucharist, and no one ever asked me if I'd been baptized or not (as it was, I was baptized as an infant by the Lutherans and again by the Baptists, who don't believe in infant baptism!). I always felt welcome taking communion in any church as a result, but I did respect the RC way when I attended mass and abstained from communion then.
Yep, most Lutherans are older... it's a dying breed, unfortunately. That's part of why I ran away to a Baptist church after the Lutherans... I got bored. But eventually I came to respect the Lutheran practices much more than the Baptists, mostly for their quiet faith and hymns that have been around for centuries (as opposed to these pop-music hymns that seem to come and go with the wind). I like stuff that lasts for a long time.