i bought just about every upgrade for the DM9 (including billy wing bolt, NT asa, virtue oled etc) and to be perfectly honest mate, the only upgrade that made any truly noticable performance difference for me was an upgrade to the ironman trigger. the DM9 is a great marker out of the box, and in my humble opinion, to get more bang for your buck, invest in a decent lightweight air system, decent hopper, then spend the rest of your hard earned cash on fine tuning yourself as a player