The benefit of keeping the H1b is that if adjustment is denied, you will not have any period out of valid nonimmigrant status, nor any unauthorized employment.
The above is intended only as general information, and does not constitute legal advice. You must speak with an attorney to discuss your individual case.
Not being on H-1B status eliminates your options if the I-485 is denied.
J Charles Ferrari Eng & Nishimura 213.622.2255 The statement above is general in nature and does not constitute legal advice, as not all the facts are known. You should retain an attorney to review all the facts specific to your case in order to receive advise specific to your case. The statement above does not create an attorney/client relationship. Answers on Avvo can only be general ones, as specific answers would require knowledge of all the facts. As such, they may or may not apply to the question.