i would add the Marten Coltrane to that list. it's very similar to the Kharma in character, price and quality.
i had the original version of the Kharma Midi Exquisites in my room for 5 months three years ago; it's an excellent speaker; very natural and balanced top to bottom. very refined, detailed and microdynamic. the original Midi diamond tweeter was just a bit prominent although it never bothered me and would not prevent me from considering them. the newer ones are slightly different. you would need to check with the distributor to find out which version you are getting.
the Kharma is an easier load than the Mini and a much easier load than the MBL's. even though you have elminiated the price of electronics; the Kharma (or Marten) will be more dynamic with the best sounding amps to my ears (which are low to mid powered). some Mini owners do use mid-powered amps in small rooms and like it. your room is not small.
overall all these speakers are very special and different enough that you should choose them based on which character you like. i could live long-term with either the Kharma or Mini; maybe not that long term with the MBL.
i'm not that familiar with that Amati to comment.
