REALLY, REALLY CONFUSED! 請教! 485 transfer or a new 485

Can someone kindly help me on this? I filed two I-140s (EA and NIW) last October.I filed I-485 with my EA case concurrently. My NIW case was approved last December. After that I have been waiting for the date from Visa bulletin. Now visa bulletin is current for NIW. My question is shall I transfer my pending 485 to the approved NIW 140 (my EA I-140 is still pending) or shall I file another 485? My lawyer thinks that transfer fails quite frequently. However, he also thinks that immigration office will not accept two 485 for one applicant. I am really really confused! What shall I do?