I've got a Rev1 and RevJrPro and I like both.
The Rev1 dry tone is what I really like.
Something a bit different with my Rev1: http://www.netmusicians.org/?section=id&value=1568
Other than trolling I'm really at a loss about Krank dislike.
Here's several with my 1990 Loopless SLO...
http://www.netmusicians.org/?section=id&value=5983
http://www.netmusicians.org/?section=id&value=10255
http://www.netmusicians.org/?section=id&value=9466
http://www.netmusicians.org/?section=id&value=7813
I've played around with the GB-ET65 mix but it didn't stay long. Both early 80's GBs and early 2000's GBs.
Also, I've mixed ET65's with quite a few other speakers and they just can't seem to find a home.
Are you using the same Meter?
Maybe your initial reading was in error.
If all of the speakers are now reading 10.5 and all of the speakers previously read ~13, the common element here is the Meter. Maybe put new batteries in the Meter.
Try a different Meter.
If you're hoping to get serious attenuation without significant tonal change, IMO you'll be disappointed. (8ohm Hot Plate)
-4db is Okay
-8db is borderline
anything more is :(