I'm guessing you mean Strawberry or Stratosphere, right? Since Steel Strings is an acoustic guitar and naturally very different on that distinction alone.
Banshee has an extra 2 lower strings, so it's great for any guitar part that needs that extra range. Metal is the obvious candidate, but I find it works well for getting a baritone guitar sound as well, and you can get a Chapman stick sound using the tapping articulation, too. The scale length on Banshee is much larger, at 30". By comparison, Strawberry has a scale length of 24.75" and Stratosphere is 25.5". That extra scale length gives the guitar a deeper tone as well as reducing the "twangy-ness" on the low pitched strings.
The articulations are different, too. Because the guitar is geared for metal, we sampled three different artificial harmonic nodes rather than just one (like Strawberry and Stratosphere have). That way you can access the fundamental, fifth, and octave harmonics. You can get some crazy Zakk Wylde squeals using the octave harmonic node, for example. You also get a few degrees of palm muted-ness, which is really important for those rock/metal chugging rhythm guitar parts.