“Why pay even half of a what an agency charges if you can get this core skill in an employee?”
I think then the question becomes one of exposure and breadth of experience.
It’s like horseradish. “To a worm in horseradish, the world is horseradish.” – Yiddish expression
All else being equal, for a UX professional, I think it’s best we expose ourselves to a multitude of experiences in different domains (it doesn’t even have to be in technology). This opens our eyes and minds to better ways of interacting with technology. For this reason, I think a UX professional operating in a UX consultancy will more likely expose him to a multitude of experiences.
That has been my personal experience having worked in a UX consultancy and an MNC…and not back in a UX consultancy.
Then again, if you are one that believes Apple creates great products with great user experiences, being that worm might not be that bad afterall, so long as you’re in an Apple..(;