I pondered that choice as well. What my research told me (and backed up with a conversation with Joe at Axiom) was that the only downside with the VP100 is the comparison to the 150. Joe commented that the 100 is in the M60 package because the M60s add to the front soundstage nicely with the VP100.

Having said that, my experience with the VP100 has been stellar. Haven't had a single second thought. Also - more $$ then become available for other stuff.