More sensitivity then the local noise floor doesn't do you any good
and might
add to your problems. Think about it. If you have 100uV of noise then a
receiver
with a 10uV threashol will need to have a signal that is above 100uV
to be heard.
A 90uV signal will be 10uV below the noise floor and lost.
It is much better to remove your local noise to the point where yoy can
use better sensitivity.
Terry