Fwiw I've had better luck without SPF records than with them (or at least without hard-fail SPF records). As far as I know, the lack of SPF never resulted in lack of delivery (and I have no delivery problems to the big providers). But my previous setup with a hardfail SPF would cause my mail to be rejected from various people's forwarding setups, especially when forwarding to corporate or university email addresses. The problematic scenario is when they have their own domain hosted somewhere with mail forwarding (e.g. via Dreamhost), that sends it onwards to their real email account hosted by an institution. The final-destination email server then sees the forwarding server as the source of the message, and bounces it for failing SPF.
Openspf.org has a page about that [1] which recommends email providers allow their users to configure authorized forwarding sources as exempt from SPF checks on their incoming mail, and default to not rejecting based on SPF when users haven't configured the preference. But in my experience few institutions follow this recommendation.
Once I ditched the SPF records, I've had no deliverability problems running my own mailserver.
Openspf.org has a page about that [1] which recommends email providers allow their users to configure authorized forwarding sources as exempt from SPF checks on their incoming mail, and default to not rejecting based on SPF when users haven't configured the preference. But in my experience few institutions follow this recommendation.
Once I ditched the SPF records, I've had no deliverability problems running my own mailserver.
[1] http://www.openspf.org/Best_Practices/Forwarding