Kingfisher. But I like them both. BBHeron can be too turquoise for my taste, but I found that a little shaking fixes that. Have to keep these inks well mixed. It might take me a bit to empty out a couple vials, but I can send you samples of both.
I haven't used heron but the kingfisher is quickly becoming my favorite blue-black. Previously it had been Iroshizuku Tsuki-yo but the price and performance of kingfisher has it beat.