The CME UF starts at the bottom octave of a regular piano, and goes 76 keys up, instead of the usual middle approach. This way you can actually do a 5 string bass emulation with the low B string. This is the reason I am seriously considering that one to go with the BK-7M I'm trying to buy. I used to hate my DGX-305 because it didn't have the lowest octave - doing blues and boogies just didn't sound right in the higher octaves to me.

But I'll have to the that CME out first before I decide. But I really like that they kept the lowest keys.