I played Insurgency 2 quite a lot and I loved the soundtrack, it was so underrated and was fitting so well with the atmosphere of the game and really immerses you into this world, however I was very disappointed when I heard some of Insurgency Sandstorms soundtracks. It feels like you guys were in a rush and didn't have time to make a good, fitting soundtrack. Since you guys are pretty good to go now me and probably a lot of other people would be very excited to get some good soundtrack.
I think the soundtracks that represented Insurgency 2 the best were Retreat ost and Menu 1.
Try to get a soundtrack that the players can remember, that gives the goosebumps when they are in a fight gearing it. This is an important part in a game like this.
I love this game, good work, keep it up.