Here's an illustration that nicely shows the difference in develo
pment flows between uniPaaS (an end-to-end development and deployment tool) v.s. doing it the usual way (a combination of Adobe Flex for the Client end, and C# for the Server end).
Unitary Development: uniPaaS (Client & Server)
And here's how it's normally done - the hard way!
Multi-tier Development: Adobe Flex (Client) & C# (Server)
When development involves buying 2 seperate programming languages, going through lots of low-level programming, and the challenge of gathering and co-ordinating 2 seperate programming teams, there is simply less chance of the end result being deployed cheaper or faster - not to mention the fact that there's less chance the application will fully meet corporate standards and expectations.