For a minute I thought I was reading advice from the Pikey thread.My experience of cat rescues and ferals would be the same as the group you mentioned .
The mum we have just taken in I would love to keep as she is a proper cat in my eyes but she would never be totally happy in a home environment .
Best to neuter and re-home to somewhere outdoors where she will be fed and given shelter . Her kittens on the other hand are very sweet people cats . Got them at just the right time .