PJiang or XBT Lao Shi - EAD question

I got laid off recently and wanted to find a new employer to transfer my H-1B, but I have no luck so far. Today I get a job offer and maybe I have to use my EAD (I485 is more than 180 days already). So,is there any big difference between using EAD and transferring H-1B? I am concerned if there is any bad effect if I use the EAD. Can you let me know soon? Million thanks!