It was tested in 1927 and evaluated as quite good, but it was not built in series, because Bartel decided to design an improved aircraft, which resulted in the Bartel BM 4 trainer, which was produced in quantity.
[1] A distinguishing feature of the BM 2 and all Bartels was an upper wing of a shorter span, because the lower and upper wing halves were interchangeable (i.e. the lower wingspan included the width of the fuselage).
Also Bartel put a stress on standardizing the construction materials used: steel pipes, metal sheet etc., in order to make production and repairs easier.
Fuselage rectangular in cross-section, plywood-covered (engine section - metal covered).
Crew of two, sitting in tandem in open cockpits, with individual windshields.