If you like a normal Hohner Marine Band, you'll love the Steve Baker Special. It has the same feel and playability as a Marine Band, but it has an extra octave worth of notes (some claim the SBS's are more airtight, but they feel the same to me). Basically, the tuning is the same as a standard, 10-hole diatonic harp but there are three extra holes which repeat the normal 1-3 holes. The good thing is that if you already know how to play a normal harmonica, then there's no learning curve - you can play this too, but with the bonus of an extra octave. The 14th hole isn't of much use. I think it's only there because a standard Hohner 365 is used as the blank for this special tuning (or maybe Hohner thinks 13 holes would be unlucky).

Keep in mind that the extra octave doesn't always mean a LOWER octave. It depends on the key. For the Keys of A and G, hole 1 on the SBS corresponds with hole 1 on a normal harp. For the Keys of C, D and F, hole 4 on the SBS is the same pitch as hole 1 on a normal harp.