So I have used Roboform for god knows how long, it sync across all my devices. Up until recently the last version, you could stick a version on a USB stick and it would allow you to load up an instance on a computer that didnt have Roboform installed. An when you took the USB out, the app disappears. I have something like 500 different passwords managed with it.
But - I also provide every site a separate e-mail.
If firstname.lastname@example.org starts getting Viagra spam, theres a good chance that they got my address from Slashdot. And when that happens, I TKO the address, it goes directly to trash.
If you're lucky enough to figure out my login - email@example.com and my password '3l13t3haxor', it is usable at absolutely zero other sites.