I'm confused about ICBMs

I have 2 systems. Can someone please help me determine if an ICBM would benefit either of them substantially:

1. 5.1 System:
M&K 750 for the front left, center, and right. M&K tripole surrounds, and a M&K Subwoofer all connected to a Denon 3300 Receiver. I use an old Denon DVD player connected via an optical cable only. This is my movie system, no DVD-Audio, no SACD, just Movie DVDs and TV.

2. Stereo System
Magnepan MMG for left and right, LFM-1 Sub connected to a Outlaw 950. I have a Sony ES SACD player hooked up as my source with both the digital connection for CDs and the Analog connections for SACD. This is my music only system (CDs and SACDs.)

In both cases I have my speakers set to small (in the processor/reciever)and have all of the bass sent to the sub. How would an ICBM change what I already have soundwise?

Thanks