The PSR2100 has all of the voices of the Tyros except for the Megavoices and Live! drums. The PSR2100 has the same operating system as the Tyros which is a big improvement over the PSR9000. I purchased two PSR2100s. On one of them I have the HDM2 system which gives me a quasi-hard drive which compensates for the lack of storage on the PSR2100 - only 1.5mb.

Beakybird

Actually the Tyros does have quite a few voices that the 2100 doesn't, besides just megas and live drum kits.

Of the Sweet!, Cool!, and Live! voices, I stand corrected that there are several Tyros voices that aren't on the the PSR2100.