Great question, and I kept trying to figure that out as I was watching. Honestly, though, I don't know, which is a good thing, I guess. Based solely on what was in the trailers that wasn't in the final product...
- There was obviously a sizable change to Saw's role/influence, and it showed.
-Bodhi's role was reportedly beefed way up, which I thought was a great decision and well-handled.
- Jyn and Cassian made it back down to the beach at one point, AFTER stealing the plans, to join the battle. I have to say, though, I liked how they "ended" their story atop the structure (save for resting on the beach at the end). Felt like more of a literal climax.
I honestly don't know if it's a Gilroy vs Edwards thing, idea-wise. I think everyone, including Edwards, likely admiteded that the movie had flaws, and Gilroy simply did what he could to address them rather than truly add his own influence/spin, if that makes sense. And for the most part, from what we can tell, I'm all for whatever decisions he/they made. With Saw, specifically, there likely just wasn't anything that could be done, given whatever restrictions they were working with. Everything else, though, looked to be a step up.