<< why is a maxi-fuse better? Colyn>>

They act faster than a circuit breaker upon overload. If you look at the time-current charts for an aircraft circuit breaker, it can take up to sixty seconds  for a Klixon circuit breaker to trip upon a 200% overload. The wiring to your hydraulic pump will most likely melt and fill the cockpit with smoke during that time.

The Maxi-Fuses will trip within 10 seconds upon a 200% overload. http://www.littelfuse.com/data/en/Data_Sheets/299.pdf

The downside is that Maxi-Fuses are not resettable. I have also read that the current rating decreases over time under heavy load. IOW, a 40A fuse might become a 30A fuse over time. I don't know if that's true or not.