Does Inquiry to USCIS help?

Friends,

I wonder whether anybody can share with his/her experience with filing an Inquiry to USCIS about I-485. Does it help?
Normally we file Inquiry due to the following reasons:
1. Case RD is out of processing time for more than 1 month;
2. Visa quota available (priority date current);
3. FBI NC issue.
I did file one Inquiry because of 1. and 2. above. I don't know what result USCIS may provide if case should have been adjudicated.

Thanks.