There are a lot of things to see, and there is most likely an order to how things will be shown. Overall, we haven't seen much of a difference, but we will see it. I have a feeling that the similarities to Alabasta is what's really going to come to play here for the differences.
Alabasta was a big event at the time of the story, which shook some things up. Crocodile was a Shikibukai that was attempting to take over a kingdom, and obtain a weapon that could help him take down al his enemies. He ultimately failed, and the most we got was him losing his position and being put in Impel Down, with then seeing a meeting about replacing the lost member. That was while Sengoku was in charge.
This arc, Doflamingo has already taken over the kingdom, and has been in control for 10 years. He turned many big figures into toys, which everyone forgot about. He deals weapons to all these factions to keep wars from going on, has a scientist creating dangerous weapons to be sold to the highest bidder, and creates artificial zoans to supply to a Yonkou. He's basically everything Crocodile wanted. When Doflamingo falls, there are going to be greater consequences, and we will see more reactions from every where.
I think this will be where Darth should get some satisfaction, and we will see how Akainu differs so much. I actually wouldn't be surprised if Akainu just straight up executed Doflamingo. He will do that to create an example to the rest if they were backstab him. We would probably see the rest of them there because Akainu will require them to attend or else. We will see Buggy and the other new one. This would also probably start a shift in Fujitora's plan, as no new member would be made. We will probably meet the other Admiral, and have some more perspective on what they are up to.
Next, we would see the reactions of different Yonkou, which means more Shanks:wub: We will see reaction from Blackbeard and his response to what happened to Burgess, Big Mom will probably respond to both that and the attack by Sanji's group. Shanks will see that Luffy is making headway in the New World, and Kaido will be enraged. With this all four of them have their sights on Luffy. This will complete the transition from the WG being the looming enemy to the Yonkou being the major, looming enemies.
This is also where we will see what all the rest of the worse generation have been up to, seeing the other alliance making headway into their plans, and seeing what the others have been doing. We'll see X-drake with the Kaido part. We'll also get to see Laws crew and Sanji's group, seeing what they've been up to, which good chances are they will be returning to Dressrosa to pick up the crew.
Biggest thing is we will get more look at the revolutionaries. We will see how Dragon reacts to what Sabo did, as well as his son's big return. We'll probably learn about their future plans and goals, as well as meet some other important figures that could be important later on.
As far as showing Burgess, Sabo, and Fujitora off, they are here to show what is to come, and how they are connected. We see a little of what they can do, and what level they might be on. Sabo is capable of taking on Burgess and Fujitora. That means all three of them are around certain levels, and all three of them can take each other on to a degree. We most likely won't get much more beyond that.
The end of this arc will really start to show that it is a new era. The 2 years was a transition phase with some new figures coming into power, but now is where the worst generation starts the new era, which is throwing the world out of balance, so it can rebalance into something new.