I agree with everything you said. I think it's a bit dark, but I do like the way his (her?) eyes and nose are lit. Maybe this photo would benefit from a crop? I would have to try it, but maybe cropping out a bit of the body at the bottom might make it more dynamic. It also feels a little soft to me. I'm not sure if that's a combination of your f-stop and distance from Angus or if it's just a soft focus.
I do like the tighter crop and angle you used - it makes it more interesting that just a snapshot of a cat. I also like the bit of extra space on the left side of the photo where Angus is looking, but you might want to try more space in the future as it makes it more dynamic. (This is a critique I've gotten a few times and I'm still working on it myself...)
I have 3 cats of my own and have yet to capture a photo of them I like. Thanks for sharing!