I can't answer your specific questions about comparing the sound of the H7 vs H8. I have a pair of H7.
I didn't need noise cancellation as these are used in my home when I don’t want to disturb others and there is no competing noise. They are very comfortable over the ear for the duration of a movie or two. I wear glasses and the headphones do not cause any pressure or problems. I prefer over the ear to on the ear.
I find the sound quality very good and I get quickly immersed in the movie. Before long I forget I am wearing them.
For noise cancelling head phones (plane travel) I have a pair of on ear Bose "cans" which are wired (not Bluetooth). They do the job but I find noise cancellation is a noise reduction device and some noise gets through and so negates the effect of excellent sound.
I hope this helps.