It is interesting to see the ppl reactions to leaders/civs that require a unconventional aproach.....
In fact most of the reactions to certain leaders ( João ( p.s Please stop butchering his name... C'mon, only 4 letters....

J-o-a-o

) being the more noticeable , but most of the BtS new ones received that kind of halfhearted reactions ) that go out of the "normal" way of playing Civ were somehow shunned until someone pointed how to use them effectivelly : I remember of some reactions to the Quechua back in vanilla days: " WTH , a warrior UU? What am I going to do it such a weak unit that obsoletes fast ( 3 cheap tech and metal ) ?"... until someone noticed that the guys eat archers for lunch......
João has two sets of strengths: Rexing and sea power... Hermit showed one ( yes , I do agree that his empire is a little overstreched, but it is nothing that can't be resolved ) ,using settler/worker and unit pumps to put the maximum number of cities in place and then working around it ( btw I remember a thread in here where it was discussed how fast could you put 6 cities in map... IIRC with a Imp leader you could get something like 6 cities in 30ishs turns

of course that would put your slider in the 0% and most likely before you could hire any specialists, but pop is power as well ... but it is a reminder of how fast you can go in that direction if you want ). This techique is somewhat dangerous if you have one of the wackos nearby, but if you can put 10 cites in place when the AI only has 5-6 , the game is in the bag with some good planning.... and you can even try ICS ( that is well and alive in Civ IV... just check
this SG )
Other option is the overseas expansion.... João coastal cities can be transformed in cash cows if you can get the water wonders and the UU fast ( a easy thing... just go by the southern tech route ) and his UB is cumulative with the collosus ( at least if you skip astro for a bit... this game is always about tradeoffs )....
The big problem is that you need to decide between this two options fast and you can go pretty wrong if you choose to go in the bad direction... But I think that the big issue is that João doesn't shine with any of the more conventional strats: both conventional SE and CE require other aproaches and as João doesn't have any of the banner traits of both ( that people like to call "economical traits" )... that makes that João SE and CE will look pretty bad in the picture until the investement start to pay off.... it that regard it reminds me Tokugawa: no "eco" traits, late UB and medieval UU... hard to leverage until the gunpowder times..... and not suprisingly ppl also like to say that Toku sucks ( at least until samurai and Gunpowder times

): it doesn't fit the more "normal" strats and you have to use them in more " out of the box" ways to make them shine.
Madscientist posted a interesting issue: the fact that is hard to pull the 2nd ring in this strat cities ( unlike Cathy ). IMHO it is not a big issue: remember that you want to maximixe # of cities , and to say the truth, you'll not be able to work more than 8 tiles for a long time if you don't aim for HR or Rep and don't have a good supply of

resources: that makes the 2nd ring a little less shiny ( of course that will require a different dotmapping, but it is doable )
P.S I'm glad that a good player like hermit agrees with me that this is a viable strat... I've been saying this for a long time ( even before BtS release..... )