I recently discovered the tree buffer which can be displayed together
with the summary.  I can even tell it to minimize the buffer (which in
fact doesn't minimize, but adjust to the needed size).

But when I read longer articles and press SPACE for the first time,
the tree buffer always becomes 0.25 of the frame height (from
gnus-win.el:gnus-configure-frame and gnus-configure-windows).

So these might need a fix (anyone with spare time out there?):

    - (setq gnus-tree-minimize t) results in minimizing not height
      adjustment in general

    - SPACE and related doesn't mix up the tree frame height

Best regards,
Sascha

-- 
Insanity is never having to say "your crazy."