Well done Nick! It's the age old software battle - wanting to build software that generalizes in order to maximize client base (and hence revenue). But general is almost never better for buyers, they prefer custom software tailored to their needs. So vSaaS is thus better for clients but harder to scale. Salesforce is great example of a highly customizable and extensible SaaS that can be customized to deliver some vertical solutions that are almost as good a custom solutions. One key for Salesforce is the ability to extend and adapt their data model - that's a key enabler.

So maybe that's where SaaS vs vSaaS will converge?