I fly both B3 and 407,
I my vieuw the 407 is the better corporate machine with the smoothest ride and a better fuel burn per mile,
On the other hand the B3 has a nicer cabin (but will only seat 6 in normal configuration) with everybody together and has the better fadec of the 2 with a bit more power hot and high and the B3 is also slightly better in autorotation
hope this helps