travel to mexico, do I have to use AP or 30 days rule

Hi
I am holding H1B and will expire on Aug 08. I filed I-485 on last Nov 07, currently it is still pending. I got both my AP and EAD, the AP will expire on Feb, 08. I am planning to make a trip to cancun, mexico, so far, I am kind of confuse about document. should I use AP or can I use 30 days visa revalidation rule. I had asked my lawyer, her answer is to use AP. I am kind hesitate to use it, mainly b/s when I return, I need to have to wait at home and go through more checks. If I can use that 30 days rule, that will be much easier. anyone has suggestion? please advice. this is my first time to use AP, any suggestion too? If I use AP,do I have to give up my current I-94?
thanks in advance