At NDC Oslo, F# in Finance and other recent events I've given versions of the talk "Succeeding with Functional-First Programming in Finance". I've also given adaptions called "Succeeding with Functional-First Programming in Industry". The slides are now available on Slide Share. The talk is based partly on material from http://fsharp.org/testimonials and other sources, I'd be happy to know of more material like this.
Some explanation: the talk does not say that functional-first programming is right "everywhere". However the talk does say the functional-first seems to be particularly effective today "for some kinds of tasks, some of the time". Likewise, the talk does not say that functional-first programming is only useful for these tasks, rather that it is particularly effective for them.
I encourage everyone to keep sharing your stories about succeeding with ANY kind of functional-first programming in industry.
And a Happy Functional-First New Year to everyone!