I went with the 50 amp breaker also. It won't cause you to burn anything up, it actually will trip quicker if a short occurs. If you are using smaller wire, less is better. I am not sure what size wire is on my "new" project boat. I still have to put the breaker on it.
I guess rather than say it trips quicker it would be more accurate to say it takes less of an overload to trip it. (50 vs. 60 amps)
By the way, you want to place the breaker as close to the battery as possible. The breaker is actually protecting the wiring more so than the device.
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