Thank you Marcus for posting this thread---I wrestle with this all the time and have done a lot of research. Relevant daily mail accounts for me are a low single digit.
In the end I agree with data drake (and others) and if it ain't broke don't fix it: open your mail at the server (CLIENT model).
With a centralized mailbox, like most are advocating, I have trust issues----all eggs in one basket is anti-instinctual to me.
Love to know in your 'poll' if these centralized clients VS. web client answers are generationally-based. Schrodinger's cat chance it is, but personal taste/needs probably dictates this decision in the end. Emails in many ways are still very personal things and to have a single entity in control of them all comes down to perception of security I suppose.
As usual, Kyrios' point of view (as devil's advocate) is just as compelling.
EDIT REASON: typo