I completed a modpack literally just the other day (monday night) which is pretty much just hexxit updated. I replaced more bows with the crossbow mod and rotten flesh to leather with another mod that does the same as the version they used in hexxit hasn't been updated. When I checked I couldn't find Harken Scythe and Xeno's Reliquary so I will have to add those in, which will make a big difference. I was missing reliquary for sure. Everything else is there though. I also added the dungeon pack mod so there's even more dungeon variety. A better mobs mod, weeping angels, and the statues and carpentry mods from attack of the b-team. The biggest problem is the loot added to chests. Each mods loot chest have to be configured manually and all item IDs have changed. So currently chests only contain either vanilla loot or loot added by the mod they were spawned by. The main dungeons aren't so bad, but battle towers loot particularly sucks. So I've tried to make it where they don't spawn as much. I haven't had much time to actually play the pack and test it out to get the dungeon spawning rate to where it feels right and make sure nothing breaks the game, but I've had a private server running for me and my buds to play on since tuesday and it hasn't crapped out yet so that's a good sign right? lol.