I have never tried the 3038's, but I will say that there is a drastic improvement in going from the 3033's to the 3035's, which I do currently have in my system. If you are contemplating buy either the 3033's or the 3035's, go right for the 3035's.
Kimber Select 3033 versus 3035 and 3038
I just tried a pair of Kimber Select 3033 speakers cables in my system. All i can say is WOW. I had actually borrowed a pair from a friend of mine. My question is does the 1035 provide a significant upgrade over the 1033?? If so, what characteristics seem to improve. How about the 1038?? Both are significantly more expensive . . .