Opinions on Royal Canin Maine Coon 31?

[Walter Coonkat]

At present, Walter (23 weeks old tomorrow) is eating Royal Canin Kitten 36 for his dry food. I see that Royal Canin makes a Maine Coon 31 dry food. Any opinions on it? Is it that much better for a MC than other good adult cat food? (I like the idea of a large kibble that he has to chew instead of inhaling! )

The size of the kitten kibble was fine several weeks ago, but now seems small compared to Walter's size. Should he be switched to a larger kibble before he is one year old?

(I guess it is because I lost my previous MC at such an early age that I'm trying to go out of my way with giving him the best food and spoiling Walter even more.)