I concur with MM. To be fair, even with the best wil in the world, they aren't going to get cosey on day one, and I am of the belief that slow and steady wins hands down every time. Patience is the winner and your update was, in my opinion, positive in the sense that they are not fighting. I would always take that hands down on day one. They are two strangers - they have to get to know each other, assume who is going to be head honcho and then accept the status quo.
Hopefully they'll be sharing a bowl of nommies tonight, snuggle down for bed and then tomorrow they will have had a sleep on it, know that the other is still there and hopefully move on a bit more.
I'm keeping everything crossed for you and Luther and Grace. xx