I see, so it's after you've created the box. I agree that there should at least be a mode where everything snaps to a full pixel. Anyhow, the Cmd+K trick would

I see, so it's after you've created the box. I agree that there should at least be a mode where everything snaps to a full pixel. Anyhow, the Cmd+K trick would be useful in your case. Also, corner radii should be preserved if you resize with the properties inspector.