[quote name='blume3']I have a 500gb in my old fat ps3. I am still debating on upgrading to the newer model. I am glad I could just switch my hd if I did.[/QUOTE]
Except that when you put the 500gb into the new system it will ask you if you want to format it and wipe everything off the HDD. So back up anything that you don't want to lose and hope you don't have any locked game saves or if you do hopefully you have PS+ to be able to upload those to the cloud to preserve them or those are gone.