I traded in my Bionic two weeks ago for my Nexus and I am very happy! My Bionic was plagued with problems that motorola didnt seem to find any reason to resolve urgently.
Get it now! Also when they tell you "you will need to buy the battery door and battery" tell them that you cannot afford to and ask if they would pay for it complimentary. They will do that I got an extended battery with the cover from them for free with my Galaxy Nexus when i traded in my Bionic.
I did an alternate replacement though. Not sure if thats what you are doing or if you are returning yours within the 14 days of getting the Bionic.