I just picked up a little miurus today. I still think suvattiis are nicer looking, but I couldn't pass up on this fish. I waited exactly one whole month from the time the LFS got the miurus puffers in stock before caving in...
My decision to get this puff was threefold:
1. I have yet to meet anyone locally as conscientious about the needs of puffers as I am. Ha ha.
2. I decided that the larger new tank I plan to make for my suvattii can easily be upgraded to a two-row tank rack, thus accomodating both types of puffer. (Also, buying the miurus ensured a need to get more tanks hooked up, although I've got lots of time before either fish risks outgrowing their current tank.)
3. I met someone else with a miurus and a suvatti: damned if I'm going to be outdone!
I haven't found much literature providing significant contrast between these two puffers. I've heard that the miurus is more active, but otherwise, there's not much difference. They're both lurkers that grow to the same size, require the same amount of space, eat the same types of food, and require the same water parameters.
Is this about right?
I can't wait until these puffs are +4" and on a steady weekly feeding routine. I'll feed 'em Saturday, and clean the tank Sunday. Too easy. That seems like a good way to keep the water nice and clean, although I seriously haven't had any such problems with any of my puffer tanks to date.
(Well, my DPs sure poop a lot.)
miurus vs suvattii
The only difference about them that I have only heard about would be their temperament. Arrowheads sound like they can put up with other Arrowheads and the Palembangs but that is only with a plethora of places for the induviduals to retreat to. And with the Congo it seems they will not tolerate any other puffers, including others of the same species, in the tank.
<80 gal> 2 GSPs & a Ceylon!
<75 gal> 3 Figure 8s & 1 Butterlfy Goby
<75 gal> *Empty*
<55 gal> 3 Gymnothorax polyuranodon (FW eel)
<30 long> Pair of Lorteti's & Irrubesco's, 1 DP, Endlers Livebearers, Clown Pleco, Royal Pleco, 2 Bumblebee Cats
<20 long> 4 Flounders
<4 gal> 2 Sparkling Gouramis & 3 ottos heavily planted
~Tihsho~
<75 gal> 3 Figure 8s & 1 Butterlfy Goby
<75 gal> *Empty*
<55 gal> 3 Gymnothorax polyuranodon (FW eel)
<30 long> Pair of Lorteti's & Irrubesco's, 1 DP, Endlers Livebearers, Clown Pleco, Royal Pleco, 2 Bumblebee Cats
<20 long> 4 Flounders
<4 gal> 2 Sparkling Gouramis & 3 ottos heavily planted
~Tihsho~
I keep hearing that the Congos are more active. So far, that seems true, though it's been less than two days since I got the little puff.
There were five 2.5" - 3" Congos together at the LFS initially. I dunno how long this mix would have lasted, since one had most of its tail bitten off. Mine has a little nip in its tail. I'm not sure about the first one that was sold, but the other two seemed in good shape. Of course, I saw the second one that was sold while it was still floating in the bag at its new home.
Any idea if earthworms are good food for these two types of fish?
There were five 2.5" - 3" Congos together at the LFS initially. I dunno how long this mix would have lasted, since one had most of its tail bitten off. Mine has a little nip in its tail. I'm not sure about the first one that was sold, but the other two seemed in good shape. Of course, I saw the second one that was sold while it was still floating in the bag at its new home.
Any idea if earthworms are good food for these two types of fish?
Some call it a product of a mis-spent youth, I call it Rock n Roll ! 
It's been about a month since I got my miurus. I've had the suvatti for probably at least six weeks.
The miurus is quite active during the day, and the suvatti is quite active at night. Neither spends a great deal of time completely buried in the sand. I'd say their activity levels and habits are about even, just on different schedules.
Both also change colors. The miurus tends to mimick its surroundings (it even turned all black once to look like some stones I have in its tank), but I think the suvattii's patterns sharpen up or fade out depending on its mood.
The miurus is quite active during the day, and the suvatti is quite active at night. Neither spends a great deal of time completely buried in the sand. I'd say their activity levels and habits are about even, just on different schedules.
Both also change colors. The miurus tends to mimick its surroundings (it even turned all black once to look like some stones I have in its tank), but I think the suvattii's patterns sharpen up or fade out depending on its mood.