To my ears the ls50 was livelier but far less colorful sounding. They gave every sound a certain sameness that I found difficult to live with. I really did like them though...
As much as I loved my Harbeths I did find that they didn't really bring out the character of each recording. Almost as if they painted every album with the same brush. Just a little more transparency and dynamics and they could have been the last speaker I ever owned.
oddly enough this is an area where i hear the c7s excell. every recording seems to have its own personality from what i have noticed. bright and thin recordings sound bright and thin with no coloration or false warmth. muddy and dull still sounds muddy and dull. but extremely well recorded / mixed recordings sound phenomenal. i have to give the harbeths high marks in this area- being able to rise to the occasion unlike other speakers i have heard. the LS50s however made sub par recordings sound better to my ears.