Unfortunately I have tried both of those and found them both wanting.
Actually I don't agree with assessment of email but only because I am coming from it as a work tool rather than a personal thing. While I agree that a lot of personal messages are sent via other means, work is almost exclusively carried out via email.
The problem here is the ever present Outlook I would imagine coupled with bespoke clients for some bigger companies.
Interestingly, I would be prepared to pay a reasonable amount of money for a good email client as it isn't something that I would expect to be free.