Maybe looking at the following to replace my Magico S-5 MK 1

I too have the S5’s, but the MkII iteration. I do a lot of low level listening and it is VERY different in this regard than its predecessor. I think Magicos are really neutral and transparent so a lot of the tonal balance boils down to the gear you have. I’m running an all tube setup (Zanden 3100 and 8120) and the sound is full, fast, sweet and very lush. The S3 MkII doesn’t share this attributes with the S5. I know you that you didn’t ask this, but I would not rule out the mk2. It is a better speaker than the ones you listed - more linear, neutral and transparent.

I like the Martens a lot, but I like my S5’s even more. They are more coherent and effortless - even with low power.

Hope this helps

Is the Zanden 3100 superior to the preamp stage integrated in the 6000 ?
Is it a good idea to couple the 3100 with the 6000 ?

I own LHC208 so I can answers any questions you might have. I have tried it wits several speakers but finally settled down on DeVore 0/96.
email me at arturgorniak@yahoo.com so I can give you my phone number and we can talk. 

You may wish to consider the Joseph Audio Pearl 3. 

I suggest that you audition the Bache Audio 002AB as a replacement for your Magicos:
http://bacheaudio.com/portfolios/bache-audio-002ab/