inbetweeners> I'm also pretty new with Hedgehog (just got mine few weeks ago) and so far mine has been a really good girl, just that for now she rather spend her time in her box and sleeping thn coming out to play (she only comes out to eat and drink) that could be coz she's still pretty young (1 month +)
If I'm not wrong its up to how you treat em, if you always do something that scare them they will end up as bad tempered hedgie that rather spend its time alone and always on defensive mode, but if you get em to trust you they will be like little angels (aka spikes down) and may even be delighted to see you (tho they can still be a bit moody when you wake em up)
Don't take my word for it tho, see what the others say, different hedgie+ different owner= different experience =D
and about cats, my bf has cats too and i sometimes bring my girl to his house. Its best to keep the hedgie away from the cats, especially if its still getting used to the environment and in progress of bonding with you. The cats might cause pressure and nervousness to the new hedgie. But today I let my cat (which stays with my bf) meet my girl and my cat was more afraid of my girl than the other way around XD My cat did try to touch her, but of course the spikes stopped her from doing anything more thn that
Olivur> omg, so cute! due to the ears she looks like a piglet with quills! /melts

I can't take nice pics like that coz my camera's shutter speed is too slow for a fast moving hedgie OTL