There's plenty of room at the bottom.
In thinking about nanotechnology today, what's most important is understanding where it leads, what nanotechnology will look like after we reach the assembler breakthrough.
Likewise nanotechnology will, once it gets under way, depend on the tools we have then and our ability to use them, and not on the steps that got us there.
I think dry nanotechnology is probably a dead-end.
Nanotechnology will let us build computers that are incredibly powerful. We'll have more power in the volume of a sugar cube than exists in the entire world today.
The really big difference is that what you make with a molecular machine can be completely precise, down to the tiniest degree of detail that can exist in the world.
The biggest fatal flaw in most fictional portrayals of nanotech - what sends those books arcing across the room - is ignoring that the nanobots need energy to do... anything.
Life is nanotechnology that works.