Andi,
Has VSL tested MIR with sibelius?
Can MIR open as a VST in Sibelius so that everything can be done from Sibelius on a single PC?
If yes to the above do we have any idea how many instances of VI such a set up can manage either with an i7 quad core or with a dual Xeon set up. Are we talking Brass Quintet or Brass Band?