I know this is an old thread but these conversations are fairly rare so I am still going to comment.
I have Fila x APBT crosses by accident....after finding an abandoned dog in the woods in Andalucia , in July...( 30 degrees c at night ) she was in a bad state and very thin.
Short version of the story...she is an APBT and was pounced on while living rough by , the local vets said, working Filas from nearby farming estates....
I kept the four babies....one almost all Fila, a big boy at 40 kg, one almost pure APBT and in chocolate brown.. different to the gold colour to his mum and siblings.
The 2 most fila..boy and girl, plus the other golden boy do not like people or dogs....chocolate brown and his mum are happy to meet anyone in true pitbull friendly fashoin.
All love a row....the girls will pull a bit for one...the boys scratch and pull enough to dig up tarmac on hot day..
Fila traits ...biggest boy will run while sniffing the path side to side like a bloodhound....3 will stop on top of high ground and survvey for a couple of minutes before running down...they can smell snakes in long grass......realise that horses are frightened of them....and biggest boy, that bark..never heard its equal, really is a weapon in itself as it properly hurts my ears.
Adding these pics for anyone who is still interested...like i said this is an old thread..