Hi Gary,
The TK60 has one binary sound file which contains all sounds.
I had an IBU2 for testing and the way you can manage the sounds is quite good, only topped by the ASP2 i assume.
The TK60 has one Connector for a speaker and you have to connect a potentiometer to a specific port to adjust the volume, so no software controlled volume.
I decided to go with the TK60 because it has really good sounds, especially the Abrams is way better than all others i listened to.
Olaf