Hey Archie, I've got 2. Started off with a male and then got a bitch pup. Because our boy was 5 years old and settled in the house I didn't want to take the chance of big fights.
They're both done and I'm so so happy to have 2. It's nice they have each other to chase when out running and they're just such gorgeous and hilarious characters that we couldn't just have one.
But remember having 2 is double trouble, double food, double vet bills, less space on the sofa as they both want to fit in beside you,hard to get someone to look after 2 dogs when going on hols. If you rent then remember there aren't that many landlords who will allow 2 dogs and run a mile when they hear 2 Staffies. - But of course it's also double pleasure and double fun.