I honestly don't remember them; the Cimmerians themselves left no impression on my mind one way or the other. I used information from that novel in Road of Kings, so I apparently didn't think they were a complete waste of time (unlike Turtledove's novel, which is a complete waste of time for me). Other than that, all I can say is that they did not leave an impression on me, for good or for ill.
I remember thinking that was JMR's worst novel, having a whole middle section that has nothing to do with the beginning or end of the novel, and I remember disliking his version of Cimmeria, but I simply do not have a recollection of the actual Cimmerians. Therefore I have no opinion on them beyond finding them unremarkable in hindsight.
I will probably re-read the Cimmerian section of that novel should I be asked to write a Cimmeria sourcebook, so I might revisit your question should that happen.