ahtohio

E2EE is a great modpack that often gets overshadowed by its 'predecessor', E2E.
People often treat it as 'modpack with bugfixes for E2E' and then compain that it changed too many things and everything is different, "It is not E2E anymore!'.
What is not obvious that maybe 3-4 years ago it was indeed a small extension + bugfixes modpack that was still majorly E2E, but with years it is already an entirely different modpack. But how can you convey this idea when your modpack is called Enigmatica 2 Expert: Extended?..
We can say that its name is its bane...

And while this modpack was indeed based on E2E, only some basic structure of E2E left - maybe gates system and basic relations between magic and tech mods - everything else was reworked, tuned and fixed. Author is trying to introduce creative ideas and make early, mid and lategame different from any other modpack that you've already seen. I may be not the biggest fan of some of these mechanics (singularities, looking at you), but others are creative, interesting and useful. Even Peaceful mode got its unique interaction!

Even skyblock mode, that is usuall 'add Ex Nihilo and it's done' is also an interesting experience - it is no longer 'sift gravel to get every resource in the pack', it is much more involved and forces to do small automations and plan routes on how to progress.
Some things that are obtained in Overworld have to be produred via complex processing chains, so Skyblock is considered 'harder' version of E2EE that tests player's knowledge. And you can go Peaceful Skyblock for even more complex progression! But it never boils down to mindless grind like 'you need 64 cobblestone for 1 furnace', everything is easy and automatable if you're 'expert' enough.

Still, I personally can't say this modpack is perfect - a difference from E2E, regular NuclearCraft was removed and NuclearCraft: Overhauled + Quantum Minecraft Dynamics were added. Those mods almost don't have an exposure to minecraft community and are incredibly complex for a game, in my opinion.
These mods force player to know each small detail on how each multiblock component works and interacts with other components, which can be interesting only for a small subset of players who like tinkering with their reactor in creative or download external Planners. QMD goes even worse - it just offers complex math formulas and expects me to do calculations before I even consider doing something. And no external Planners this time. I personally don't like mods with such 'figure out yourself' approach.
Still, it is not mandatory to explore those mods to the fullest and some alternative ways exist (+schematics), so it is passable and you can complete pack almost without exposure to NCO or QMD.

Modpack performance is superb, author definitely has some obsession and constantly tries to make loading time as small as possible and the whole gaming experience smooth. It can be even be migrated to Java 25 in just few steps, adding even more performance gains.
This modpack is still actively supported and new versions with bugfixes or small changes are published almost each month. Together with active community in Discord it is comforting that you're playing 'active' modpack and not some fossil which was abandoned 7 years ago and got no updates at least to such basic mods like AE2.

All in all, it is one of the best modpacks I've ever seen and it can hold its stand even compared to such superstars like DJ2 or original E2E, so I urge you to try it.