How friendly would they be outsiders in the local residential areas though? Not a rhetorical question, genuinely asking here.
Egyptians are one of the most friendliest people. Yes there are the ones that wanna scam you for money, but do you blame them, they live in a third world country that relies on their tourism. Unemployment is high for locals which doesn't help. The poor can't pay for education so they end up working in "tourism" and that's where the scamming of tourists comes in as they need the money to survive.
A local educated engineer with a degree gets 300LB a month, thats £35 a month to feed and cloth himself and his family. The government dont have schemes to help the poor like they do here in the UK so what can they do to survive? It's not pretty.
But like I said I'm not going to the touristy parts, I'll be living amongst the "upper class" people who I would say are the equivalent of out "middle class" i.e. their own house, car, enough money to get by and some for luxuries etc.. From all the research done not one person in their blogs/forum posts said they were treated badly by one of these "upper class" Egyptians.