I just want to report that I recently put Helicore Hybrid Mediums on my bass, and I absolutely love them. I've had a similar experience to @PBandJazzBass where the Evahs sound great in the practice room but kind of get buried in a live situation. I find that they sound and feel just perfect right out of the package, and I think the tension is a lot more balanced for my bass than the S42 Weichs I had on before the Evahs. I think the sound is distinctly different from the Spiro steel sound, as well. I seem to remember reading that the wrap has more nickel than Spiros, but I can't find that info anywhere now, so perhaps I'm imagining things. It certainly has a different feel under the fingers to me, and I prefer it. I read so many reports of people enjoying new HHs but that they die quickly, and I'm wondering whether that has something to do with individual differences in skin chemistry. I also play guitar, and it's common knowledge that certain players just eat through strings where others can play on the same set for months. I certainly fall into the latter category, so I'm hoping this set will last me a while!