There has also been some discussion on whether to put those tags on your carry-on or on your checked luggage. I'll try to summarize what I remember:

Pro Carry-on

• LH gate agent may let you pass with an oversized bag and instead pick on the person behind you with a normal-sized bag.

Contra Carry-on

• fellow passengers who recognize the tag may think your a snob trying to show off with those tags that should go on your checked-in bags

Pro Check-in

• On LH flights the bags get loaded close to the door and come out first

Contra Check-in

• Tags disappear
• Loading close to the door doesn't really seem to work all that often, and you'll get the priority tag as SEN anyway.

HTB.