Love the game! Question about mods...

Hey all.

Bought the game Friday and have already put in 15 hours. Rare for me!

I am curious about mods. I know there are the two big ones, New Threat Upgrade and Pact - which add/improve a lot of the models and behaviours in the game.

Should I complete all the base content first without installing them, or is it better with them added from the offset? Also, I guess they may change the balance so perhaps things are broken with them on if not specifically built with them?

Challenge increase isn't an issue - if I fail a mission 20 times but it is winnable I'll enjoy the learning process!

Also - can anyone suggest any mission packs either compatible with these mods, or just the base game, that are working well with the recent game updates?

Thanks!