Hi,
Using handbrake would give you the opportunity to create a copy with better audio and less video compression than what is available on itunes. If you use the ATV preset I can't say for sure but my guess is that is is going to be close to an itunes download so you won't gain a lot by ripping the BR disc if you use the ATV preset vs just getting the itunes version.
The Force Awakens has a Disney Digital HD copy of the movie. There is no longer a disc with an standard resolution version of the movie that you have to RIP to itunes like in the old days. The Disney digital copies are part of Disney Movies Anywhere so as long as you have an account, which is free, you can link it to any other digital seller: itunes, amazon, microsoft, google, Vudu. If you have everything linked and you buy a Disney movie like The Force Awakens on Vudu it will show up on your iTunes account and all other linked services. So, the digital HD version you get by buying the Blu ray of the movie is exactly the same as buying it on itunes including all special features available on itunes. I noticed that you get the itunes special features no matter where you buy the disney digital copy, on itunes, any of the other digital sellers or if you use the code that comes with the blu ray but to get the special features on VUDU you have to buy the movie in VUDU.