Very immersive zombie apocalypse with a few problems

Overall the modpack is nice, very immersive, with awesome shaders making it kino experience. The pack is very rewarding for exploring which is risky, but gives the player access to otherwise hardly obtainable tech. Kudos to the creators for making Refined Storage easily obtainable in this way, while not giving up the whole tech, but just the necessities. There are some issues me and my friends encountered along the way:

• The difficulty was not linearly going up, but in rather big surprise leaps. You get used to some level of horde and suddenly you have boomer making pile of rubbish out of your base. And then next, and next...
• When raiding some more difficult structures with my friends, the enemy count jumped so high, that our FPS dropped from 144 to 20-30, adding yet another level of difficulty.
• Very unfortunate that Immersive Engineering and the car mod requires command block to be properly spawned, as on our server we encountered quite a lot of command blocks and hammers just lying around. (I didn't see any command blocks in single player though)
• My last issue is with story, so it's going to be spoiler. The endgame was just anticlimactic. You build you base, making it stronger, taking on stronger and stronger foes, developing a cure that could save the world, and it's just an instant weakness with golden apple (that you don't even have to craft as there's plenty of it all around the world). And The Abyss is only good for obtaining of the brain, as all of the resources that are there are useless as you've already reached the end of the game. It's such a shame, especially considering how cool the laboratory and military bases are.

My (and my friends as we concluded this together) overall rating would be 3.5/5. It was nice experience, just enough in playtime to satisfy our Christmas tradition.
Closing note, I haven't played other zombie modpacks, so I can't really compare it to others, so take this info into account as well.
Playtime: 190 ingame days ~ 60h (3 people on the server, 190 is average)