I have reviewed the sales cloud and platform edition comparisons. There is no direct comparison but from my understanding platform enterprise is the same as sales enterprise minus the standard CRM objects: Opportunity, Leads, Cases, Forecasts, and Solutions.
Are these the only differences?
The thing that makes me believe I am missing something is that platform enterprise which seems to have all the force.com functionality minus some of the pre-built standard objects is $25/user/month while professional edition which is missing major pieces of functionality is $65/user/month.
Also, according to the user license types documentation:
Salesforce platform license: This license is not available for new customers.
So what kind of user licenses do you actually get when you buy a platform enterprise edition?