+1 The Blues are high tension compared to, for example, DR's, but man, the blacks are HIGH tension... too much for me, and a bit too ganky in the upper mids (at least the steels).
just got some blue label steels in to put on my 78 jazz. they replaced a set of lo riders and they are ever so slightly higher tension than the drs as i now have a touch more relief than i did before.