Wow! I had been using Fat Beams on my Jazz Bass and just for kicks switched to Hi Beams for my last set, I cannot believe how much different they sound to me?! I'm not sure which I like better but initial impressions have me leaning towards Fat Beams. The Hi Beams definitely seem to have a little more sizzle but they also seem to be deeper sounding as well. I think what everyone says is true about the mid content. The Fat Beams seem to have that extra hi mid that isn't in the Hi Beams. I cannot believe how different my bass sounds with just a different set of strings.