I could definitely be the poster-child for BOS. Building on their framework has moved my business from being held back by our systems to being able to rapidly deploy new profitable software features to my customers based on a robust foundation.
BOS is providing the tech foundation for several companies that we are bringing together under one management group. We were this close to signing a deal with Salesforce when we heard about BOS.
I have a pretty complicated business process that I used to run with a lot of spreadsheets and a few off-the-shelf technologies. BOS has helped me turn that all into an actual product with the security my business requires.