Maybe recent imports have problems but i got one from a fellow in michigan that originally got it from Fish Room Plus and he's never been anything but the easiest puffer i've worked with. He sits on his sand or hides under his driftwood and eats nightcrawlers, worms, small fish, (nothing thawed frozen so far)...he begs for food when ever he sees anyone. To top it off if you can see him its a 99% assurance that he's watching you no matter where in the room you are.
Very interesting species, but i woudlnt be too game to try keeping others with it, though i've heard of some people keeping multiples together, when they have a lot of visual barriers and hiding places.
Mine is in straight fresh water and i've had him for....almost five months now.
BTW Fish Room Plus seems to be the easiest place to find them on the net if you're looking and if this fish is any show of quality you wont be dissappointed (no i've never ordered from him but i've never spoken with anyone who has been less than happy). That and he humors a great many emails asking for pics from me on other sites.
Jason