He's becoming overrated based on reputation.
I guess Eze is stronger and probably more durable, better ball carrier as well, apart from that Maddison is a far better passer, better at dictating, close control, finishing, first touch/technique and is more likely to unlock a low block.
If they're both on the pitch together I can see them taking up the same zones and getting in each others way.
Interesting following the debate on where Eze would play for us. My opinion for what it's worth:
1. Eze predominantly played as a LWF / inside left for Palace last season, but is also very effective as a #10.
2. Maddison will unlikely play 55 games this season. Based on history I'd say 30-35 is more likely.
3. Having the luxury of rotating Maddison and Eze, or playing both against inferior / low block teams would be incredible, and make us an exciting team to watch.
4. Maddison may even be played in a deeper CM position in some games, similar to how Damsgaard operated for Frank at Brentford.
5. I think Kulusevski will be used predominantly as a RWF by Frank, as he likes his WFs to come inside. Kulu operating as an inside forward plays to all of his strengths (as a kind of hybrid RWF, false 9, #10), and gets him in and around the box where he is most dangerous.
However ....
6. As we just spent £30M on Tel, and still have Son, I expect those 2 to be the primary inside left forward options (rotation). Both's main strength is shifting the ball to get a half yard and shooting right footed from the LHS of the penalty box. I think we'll be set up to get them on the ball in that area, and let their striking technique do the rest.
7. I also think Frank will want to see what he has t work with before we sign anyone. We know he is a big fan of Johnson. He also name checked Solanke, Tel and Maddison in his first interviews, so is likely planning around using them.
Ultimately I'd be over the moon if we signed Eze, he is a talented and exciting player with great technique and would improve us wherever he played, but at the same time would not be too disappointed if we did not. I feel this squad has a lot more to it than people think. It came 5th the season before last and that was before we added Bergvall, Gray, Danso, Takai, Odobert, Tel, Solanke, Kinsky, and saw the emergence of Spence and Moore as first team players. I think Frank and his coaching team will have a fascinating pre-season, and I am really excited as to how we will play, and how much our players will improve in a system that is flexible and will be tailored to their strengths.