Me?What is the main reason you´r playing Monster?
LG Chakratos
It got more toys for me to play with The pack is bigger and contains a lot of interesting stuff, but at the expense of "balance" maybe. But I don't mind that as I play MC as a sandbox game, and I can regulate myself and don't have to choose the "best" or "most overpowered" solution. It simply has more building materials, automation options and just stuff in general to play around with.
But it does contain a LOT and there are stuff I never use. So I have disabled several mods and kinda wished I had disabled a few more now that I got further into the build.