By default, I go with digital. Just the fact that I can have 80-90% of my collection with me wherever I go is a huge plus. Additionally, I don't have to deal with long lines and storage. However, since I'm predominantly a Marvel reader and most of their paper versions include a bonus digital code (even trades), I'll buy the paper and redeem the code.
It also helps that I work a block away from Midtown Comics in NYC - so it's not a huge deal to hit the shop. Just stop in before work, pick up my copies and redeem the codes whenever I get a chance. If I had to go out of my way for paper versions, I probably wouldn't bother.
I'm sure Bradley Cooper will be good, and I think his voice is a good fit as well. I just really don't get why they always hire big name actors for these types of roles when they could get terrific seasoned voice actors for a fraction of the cost.
B/c voice actors don't have box office power. The general public isn't going to head to the movies because Nolan North is voicing a character - Bradley Cooper and (unofficially) Vin Diesel? Yea, they will.
That's the gist of it. Marvel is a business. If they could cast "no-name" voice actors for these characters and expect the same box office performance that they could with Cooper and Diesel, they would.