The single reason that I choose gmail over desktop clients are the conversations - the ability to see all email bodies of one email exchange in a single page is

The single reason that I choose gmail over desktop clients are the conversations - the ability to see all email bodies of one email exchange in a single page is indispensable for me. Another smaller reason is a search. If some desktop client would implement conversations (but by displaying email bodies, not only headers like Outlook or Thunderbird do), I would probably switch.