The huge attention to bits and pieces in many ways

(I am one of "developers" of this masterpiece, being the one that invented Peaceful-only mode in most of ways, gave more ores to planets and overhauled Numismatic Dynamo to support every metal.)

There is a lot of ways to where to start with this...

The amount of custom content and mechanics and definitely a highlight. Just look into all new JEI categories, that provide additional great info on all your obscur-ish and favorite mods! The author of this even codes their own "mods" in crafttweaker's script for better experience!

The skyblock mode is also one of a kind, being technically active in normal overworld in terms of changes, which made a huge impact on how resources are obtained... with burning pieces in liquids, crushing unusual blocks, exploiting the weak animals for their drops and other things; it is very interesting once you get past gimmick-infused early game.

The questbook is amazing for mods where effort was done, such as Thaumcraft-verse; many bits and pieces are explained in a grid of quests, that even reward you with even more bits and pieces (curious, isn't it?), and ending with overhaul to Thaumic Additions' items that are no longer just "the OP item takes effort" alloys for TC.

Speaking of addons... there is a lot of them, for Tinkers, for AE2, for TC (as mentioned before), for IE... they expand on a lot of stuff that is set up by their parent mods.

Changes to mods themselves (via ASM modifying) are widespread too, mostly to get around limitations or to put it above and beyond what it was designed for, like accepting thousands of RF/t or dozens of items. The ability to do it at all is inspiring.

Non-linearity of original E2E is kept here and upgraded to heaven, with routes to get around needing to do technical or magical progression, or killing any bosses; this part is not completely finished, but the details and recipes needed to skip doing machines, if you are wizard by blood, is nothing short of astonishment.

Ore processing... oh the new ore processing line... you start with normal native clusters and then ascend to increasingly more complicated magical processes to get more powerful ore chunks that are smelt into various amount of materials, depending on how much effort you put into it. IMO, very good custom mechanic, that prompts as much engagement as you decide.

Computers. There is a lot of programming you can do, in any way you want. And it is all useful in some capacity. You should like robots and mechas as tech guy watching this review, isn't it?

Now for parts that I dislike:

• I do not agree with all gimmicks done to make early game more exciting; sometimes enough fun is enough, and manual work, that is automated by delegating this manual work to robots, could be tiring to handle.
• While skips done by dedicating your attention to obscure parts are exciting in their own, it can lose that charm once the way to them is discovered somewhere else and it just becomes 4.44x stronger way to get certain resources via this funny gimmick (that is sometimes incomprehensible, like IC2 crops).
• Despite how combat-focused the pack is at times, via TConEvo and buffs to TC and I&F, there is not many enemies to fight; your targets are mostly not-very-difficult bosses and enemies buffed by Scaling Health mechanic.
• Despite overhaul to UUM line and replication, the item values are still kind of unbalanced, with early game items costing a lot of matter and midgame materials costing almost nothing.
• The endgame in general is mostly the same, you go for same complex grind on top of ultimate table and get ultimate ingot to make ultimate utilities... There is a lot of things that speed that up like PackagedAuto and other AE2 extensions, so it is at least fun to set up.
• There is some other minor things I wanted to mention, but can't remember. ech.

Playtime: around 400 hours for Peaceful, 51 hours for Conflux IV%, ~30 hours on latest alpha in Peaceful.
9.5/10.