Ok it's been over a month...
We got Rory over a month ago now. He's around 7.5 months old, around 4kg let's say. We've had Lily since July and she's around 18 months old and only about 2.5kg.
Well the first thing is, Rory is clearly bullying her. She'll be sleeping somewhere, he'll just go up and steal her space. Sometimes she seems withdrawn and upset too, most of the time she's fine. She's always been fairly chilled out, whereas Rory is nuts.
Which leads me on to the second thing... it's almost like ALL he knows is play! You can't give him a scrudge, because within a minute he's biting you or on his back pushing your hands away trying to bite you. He'll be purring, he'll do it whilst laying on your lap but it's starting to really annoy me!
Thirdly, he doesn't bury his waste in the litter tray which is seriously annoying.