I think high c strings are great for solo bass stuff where the bass doesn't really have to compete in a mix of instruments. I always enjoyed it playing at home by myself. But playing with my band was a completely different situation. I always found that playing the same note on the g string a few frets higher cut through the band better. The high c is fun for tapping parts, chords, and stuff. I just think it depends on the instrumentation of the people you jam with. For me high C just didn't cut through with my band the way all the other strings do. In reality the extra range isn't the point. It's not that much more range and you'll have to reach farther to the other strings so unless your going to be using chords or tapping parts it's not that useful. You'll rarely ever find your self playing 24th fret on a high c string other than to just see how high it goes. I played a 7 string for a couple years tuned f#beadgc, and I'm back to playing a 5. And every single thing I wrote with my band on seven string I can play on 5 string either in standard beadg or dropping the b string to A. There's also other ways to hit higher notes above the range of a 5 string. Steve Bailey has a lesson on harmonics on YouTube from the warwick factory. I spent a lot of time working on those techniques And it'll allow you to get another full octave out of the bass instead of just a 4th like adding the high c does.
