For the caste it was designed to work for,
this governmental setup did work well.
In fact, it was arguably the most successful substantially-democratic
government in history for the people it was designed to be successful for:
it lasted longer than any other (somewhere between
580 and 1040 years) despite many
external enemies and dangers, plus a social setup that would seem inherently unstable and sick.
Should we dismiss Sparta (and/or dismiss range voting)
because Spartan society contained a lot of (to modern eyes)
disagreeable features? No. We should learn what we can from it. As far as I can tell,
Sparta had its problems, but range voting was not one of them.
If you disagree, then ask yourself: should we dismiss the whole idea of
democracy just because Athens had a lot of disagreeable features?