Bumptious has a negative connotation; used to describe off-putting confidence. His bumptious tone during the meeting turned his colleagues off.
Pro Tip 2/3
Not Complimentary
Avoid using 'bumptious' for someone you wish to compliment; it implies arrogance. Calling her bumptious after her presentation can be perceived as an insult.
Pro Tip 3/3
Personal Interactions
Use 'bumptious' to critique social behavior, not professional skills or knowledge. His bumptious manner at social events often leads to awkward situations.