Because I play the Chapman Stick, I tend to mess with standard sets of strings on my basses as low as (low-to-high) C# F# B E. Still a sharp key, fret markers don't make me insane, and I like the looser tension - as the Stick is lower tension (although special design strings). But if I were playing with mates, who knows. My guitars have mediums & I never tune to Standard they are always Joni Tunings or some such pertubation. The Stick is a keyless instrument (no open strings and fret markers are five frets apart which makes sense in 4ths & 5ths tunings) so my brain has kinda exploded...I currently do not own 5-string, but when I did, it was EADGC and I would detune to D when needed. Of course I do also have a 8-string fretless that sounds bonkers when the E's are tuned to C and the other octaves strings are tuned down a 4th...