Can I use "not nearly so" in different contexts.

Den   Thu Oct 08, 2009 7:29 am GMT
Hello, everybody!

Is "not nearly as/so" phrase only used when comparing something with something, for example, "not nearly as important as you think", or "not nearly so bad as the media says".
Can I use this phrase in another context:
"Do you think Sandra is a good professional?"
"Oh... not nearly so... well... I think she's quite good at her knowledge of the subject, whereas she's not good as a person"
...where I can't say for sure that she's a good professional, as well as she isn't.
And if this structure isn't grammatically correct, what other structures I can use?