If my memory is correct the total is 30 amps for the Fuzeblock and 10 amps for an individual circuit. The ability to choose between switched or always connected to the power is great. I did not mount mine under the seat, I found space up front on the left side.
Check out this thread for how I mounted it: http://advrider.com/forums/showthread.php?t=812460
There is a switched connector up under the beak for a GPS that I am using to switch the Fuzeblock. The connector that mates to it is about $15 at the dealer.