Oh, no...Upper Norwood wasn't bad. We were near a lovely park. The parts of Croydon itself I'm familiar with are grim, but there are nice streets and less nice streets all over London. If you're an urban person, you may be happier in the city. But, as contrex pointed out, there are some very lovely, leafy places out from town, within commuting distance of work.
I guess the thing is -- if you can, to get a look at where you're going before you get there. Or, if you can't, don't lock yourself into a long-term commitment before you have to.