I think it really depends on where you are, the environment, etc. I've read on this thread Ed8 users are shocked someone wore it in the streets of NYC. However, I used to wear my Ed8LEs out around Tokyo a lot and it wasn't really a problem (personally the Ed8LEs seem less flashy than the Ruth though) and it's compact enough to throw it into my satchel.
SigPros to me, due to the size and the length of the cable, seem to scream out more. And despite the ability to fold the cups, were bigger to throw into the satchel. Having said that, I had a personal preference of the SigPros SQ over the Ed8's. When talking to the manager of TImeLord (Japan's Ultrasone distributor), I told her it would have been great if they could have put in the SigPro's SQ into the Ed8's design.
My TH-900, I tried taking it out only a couple of times but due to their poor isolation, felt it was pointless taking them out so they've been staying at home.