Currently I use the extension Lastpass to store my passwords. The advantages are: 1) each PW is unique and strong (about forty of them which I could never remember otherwise); 2) the PW are stored on "their" servers in encrypted form so even if their servers were hacked, the PW would still be protected at least until they regained control of their servers AND LP does not have the master PW so even they cannot read my PW; 3) my PW are synced to my other devices (ipad, laptop) by my simply installing LP and logging into it with my master PW; 4) my PW are easily changed and on a regular basis since LP makes this process so easy.
The only disadvantage to date is that in IE LP forces me to have an extra toolbar in order to work whereas in FF or Chrome it is a simple button that adds to my taskbar.
Now... some still argue that having one's passwords stored on a server rather than one's own computer is putting them at risk. I will add that my banking and amazon pw are NOT stored anywhere but are in my mind. Still... I can partially see their argument against LP and Roboform managers.
NOW... compare the above to Firefox. As I understand it, the passwords are stored on my own computer in encrypted form and under a master password... correct? Would they easily sync with my other devices? Would they be considered safer from hacking than they are currently on LP or Roboform? What are the advantages to letting FF do this rather than an extension like LP?