Is there an alternative private messsage module that integrates with Views? As far as I can tell it's the only real solution on the block. But it has major drawbacks that make it unusable for most sites. Mainly its not built with views, therefore easy customization is out of the question unless I change the code.

Are there any alternatives, paid or free, that beat privatemsg and integrate with Views?
You can also consider theming Private Message.  Private Message is an extremely powerful module that offers a much higher degree of customization than some sites may need (messages can be sent to users + roles at the same time, etc.)

For my site, I added several tweaks to actually limit/reduce Private Message's functionality (users can only have one thread per user, users can only message one user at a time, users cannot send more than three messages in a row to the same user, etc.)

Messaging systems are pretty complex so I found it easier to start with the huge number of options Private Message provides and then reduce them.

You could also help work on privatemsg views integration, though this is a huge project.