I thought Walz's first ever night as a color analyst was his best. Excellent insight despite, as would be expected, a very rough presentation. But steep downhill from there. Now, his filibuster style of delivery is so incessantly long, that his points get lost in all the verbiage. Like when Greenlay does color, I'm turning off the sound. Greenlay appears to be a nice guy, but he rarely offers any insight. IMO, VERY lazy preparation.
Like you indicated, Nanne was excellent. I'm hopeful on Carter. Still raw, but informative and MUCH, MUCH more succinct than Walz.
And as Theresa opined, oh what a joy it would be to listen to a Forslund or Kelly on a nightly basis. Throw in Reaugh, Hedican, Fox, Panger or Olzcyk to do color and I would be in regional hockey broadcast heaven.