I have one player who thumbed his nose at the idea and invested heavily into his talent tree to start (he actually bought all the way down to Dedication).
The group has earned 125xp so far, but he's been pretty much a badass all the way through. It sure doesn't feel like he's missed out or made a mistake in any way.
I guess I'd say he's weaker at the general stuff, but within his role he feels much stronger for it.