Hi, my two cents
I own three medium scales (you can see them in the medium scale bass club), i play them almost daily, and i play gigs quite often: i really play everything, from Georgia on my mind (with drummer with brushes) to Motorhead via My Sharona, always play medium scales (except with a metal band), never had anyone complaining my sound or saying that the sound was muddy, different ecc..
When I explain people that my bass is medium scale, the majority of people (many musicians) simply smiles and adknowledge they didn't even notice it neither for the sound nor for the size ( i have to say that i'm relatively small, 170 cm. so the medium scale is proportioned).
Regarding the matter of the lower tension of strings, i know the physical theory but all i have to say is that sometimes theory tells one thing and your ears another (don't want to offend anyone, just my opinion); as I said I played countless hours with medium scales and nobody, musicians and people listening, ever told me that my basses sounded different from long scales...really nobody.
I play also with a hard rock/metal band who plays with the guitars and basses tuned one tone lower, i didn't liked the feel on the strings so I tried a long scale bass (a sterling sb14) believing/hoping that the 2 inches could have solved the problem, but the feeling was more or less the same, so the only solution was to switch to a 5 string and translate the songs.