>>536692162
I picked up 1 after playing 2 and I'm having a decent time with it. It's a very different game and it's a lot harder to solo. I was failing missions on Easy because it is absurdly easy to die in Helldivers 1 and you only get 2 auto revives. If you can get past the beginner levels on your own and start SOSing every game there are still people playing, just gotta play at good hours.
The DLC is like every warbond would be for 2, but some stuff is straight P2W. I'd recommend disabling all of it before going in, otherwise you have instant access to tons of OP stuff and won't get the newbie experience, which is important because you unlock newstratagems by completing operations.