I like ammeters.
Im building a whole new panel for the ol' boat.
For the reason stated by the OP I don't like the idea of series ammeters, so I'm putting a shunt ammeter in mine. I put the shunt(50-Milivolt) in the negative circuit just after the negative buss on it's return to the battery.
I'm not sure if this setup will show all the potential leaks to ground, but it's more to help guide me in power management. Possibly some improved safety too, as any contact with the big shunt post to ground, will not short the curent. Nothing like dropping a wrench on a terminal post to wake you up!