I still like Colosseum better overall, but there's no denying it was a huge mechanical improvement. Shadow pokemon were revamped so that entering hyper mode(forget what XD called it but it's basically the same thing) so entering it doesn't waste your turn but that state does chip damage while there's a bigger pool of shadow moves that DO have the physical/special split and most of which don't have recoil. That makes them a lot more usable and a lot more interesting to face in battle, however they made the mistake of making the purification chamber too efficient so the average player quickly starts relying on it instead of switching around their team and never gets to play around with most of the updated moves. Saving from the menu is a godsend, having the ability to catch some wild mons especially so they can be used as trade fodder is somewhat useful if lacking variety and requiring more effort and patience than the available mons are worth, there's a few puzzles for the player to interact with even if they are super basic, and being able to buy balls at any shop is a huge time saver when you consider how many you'll go through even ignoring wild mons with the longer list of shadow pokemon. Where it loses points is the loss of stuff like Phenac Stadium colosseum challenge and the under, more tutorials that at that point were already getting redundant in main series but as a direct sequel to a game that was better for tucking that info away in an easily accessible yet not in your face spot really didn't need to be so obnoxious, the writing's a lot closer to main series than Colosseum's in tone yet most of the plot elements were recycled so the big twists were even easier to see coming and characters lacked depth compared to Colosseum's (Duking and Sylva mainly, but 2 is more than just Eldes), and the new areas they added although nice on their own didn't quite fit the region (2 grassy areas and a port in spots that don't add up when you compare the world maps.)
