I personally don't remember much in the way of pingers with GHD 1. Dry slotting hurt us a lot more than any mixing.
Now with 12/31/2007, mixing was absolutely a problem.
And in all fairness, there were the positive busts we never talk about, such as Feb 5-6, 2008. 4-8" with TSSN+ in the vicinity that fell in a span of 2 hours (after spending much of the day with a light icy mix).