I rarely join in these conversations as they invariably degenerate into a "nuh-uh" "uh-huh" back-and-forth, but I have to say that *as of today* I think a Lone Wolf, Nomad and Hardcore all on the same person denotes a certain amount of something. Call it skill, experience, situational awareness, patience, whatever, but any player with those three banners (and probably a few others acquired in passing from just playing the game) is probably above-average.
This is of course impossible to tell while in a lobby unless you open a browser and look to see whether that person's N7 HQ is public. It also becomes less and less of a valid indication by the day, this weekend if Squad Elite is corrected, I bet anyone who wants "Mass Effect" will have it, or be very close to having it.
I have sometimes wondered if it should be possible to see a collection of a person's acquired banners in the lobby, either on a shifting- or scrolling basis like Promotions, N7 and Challenge Points, or as an addition to the loadout screen. Then again, since it's such a diminishing value, it's probably not worth patching the game for and not likely to happen.
Z.