No, you will get more noise because it is Behringer.
But seriously....Yes you will pick up more "room" sound with an omni, which may or may not be good, depending on the quality of acoustics in your room.
1. The behringer B1 is a cardiod mic - unidirectional. It cannot do omnidirectional.
2. All rooms are acoustic. They have no choice. It's the acoustic treatments to the room that are important. Minimizing reflections, standing waves, use of bass traps, etc.