GFI Breakers vs sockets ?

[monza]

Anyone using them, do they work well? Do they ever trip when they should not? A electritian friend said he has heard of nuisance tripping with both the breaker and the socket. Anyone know any thing about that.
Just deciding on using breakers or GFI outlets any comments?

I have never used a GFI before who uses them? Should every thing used in a aquarium be pluged into one?

Dave