Martin Logan CLS which model?

[gouldglen]

Hello all, this is my first post! I owned a pair of CLS in the mid eighties, the first version which I sold. I still regret that move. I am on the hunt for a used pair and trying to decide which CLS version to get. My understanding is the CLS 11 and 11z were considerably more "reliable" and perhaps better sonically. I welcome your thoughts on this!