I listened to PSB Image 2Bs before getting my first set of Axioms... I believe the 2B was replaced by the 25 but not sure. Compared to the Axioms (M2 or M3) I felt that the PSB had better bass and could play a bit louder but was definitely not as "clear and crisp" in the midrange. Vocals, acoustic guitar, even the harmonics on electric bass seemed to be more accurate on the Axioims.

I did not get to compare them side by side so treat this as "low quality information"

M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8