Verbina29

The pack barely feels configured or cohesive. Recipes feel changed just for the sake of it rather than actual balancing, many equivalent items are wildly more or less expensive seemingly at random.
The quest layouts are incredibly disorganized and overstimulating. They're difficult to navigate, and feel like they were designed for zoomed-out aesthetics rather than actually being used and navigated by players. Quest rewards are either completely useless, mildly useful (two or three of a random resource from the mod), or just another of the item you just made, with little rhyme or reason. The quests themselves are often annoyingly specific, such as the AE2 Wireless Terminal quest requiring you to make both a non-crafting wireless terminal and a crafting one, despite being able to create the better crafting terminal without first creating the basic terminal. Quests are also scattered across many chapters, with the same item often completing several nearly-identical quests, with the same nigh-pointless rewards that just fill up your inventory. The quests also teach you less about the mod than the actual guide books, which isn't great for a large kitchen sink pack that will likely be many people's first experience with some mods.
Things are generally poorly configured. FTB Chunks' claims don't allow doors by default, which should be one of the first things that a playtester would discover and change. It really just feels like a few hundred mods thrown together with a bunch of low-effort quests.
The performance is terrible, especially on low-end machines and medium-end servers.
Silent's Gems has been given a smeltery-equivalent, which completely removes the unique aspects of the mod, and turns it into a TiCon ripoff. Many recipes feel like they've been changed just so that they can contribute to the ATM Star, rather than actual balancing reasons.

Overall, it feels like the pack wasn't playtested at all, as most ATM packs do. Poor optimization, poor balancing, and very little configuration.