Lyra Kleos SL

I found references to the Kleos SL on the Lyra website and several postings which seems to be a low output "special edition" model. Can someone please explain the sonic differences to the "normal" Kleos?
Have you seen this thread on the naim forum?

There could be practical reasons for wanting lower output. If someone has a SUT designed for a lower output cart, the regular version cart would be inappropriate.

I think the SL is .25mV and the regular is .5mV.
Thank you for the link which is quite informative.
It seems astonishing though that there is such a price difference.