Nearly 1 GB of different sounds, from piano to moog, wooden instruments and strings, it includes everything...when you buy the complete pack ($20). Which means it's a full expander for less than $30.
Coupled with Mobile Keys from Line 6 for live use with a power trio and you have an instrument easy to transport, cable and setup.
I sing and play guitar in a trio, so my idea is to use sampletank to trigger some loops and sounds live. I prepare my loops on three maxi tracks and keep a free one to play a sound live (organ, for example). The result is very satisfying, considering the investment. Sounds are quite all right, without being exceptional. Creating loops from 1 to 16 bars is child's play, quantization, midi event recording, from 1 to 4 tracks with rerecording
In short, a mini sequencer that is ideal for live applications, at least for what I do as a guitarist.