I use sounds from Superior Drummer. Personally I think the especially the SD snare sounds are better than the 2box sounds; they sound a bit richer. I think this is because all 2box sounds are compressed, but unfortunately the compression is not lossless. Some 2box sounds are more compressed than others. I'll try to explain what I mean.
You can see how much a sound is compressed by tuning up the "Tune" parameter to its maximum. For most sounds you end up at 4.0 or 5.0, meaning that the pitch now is 4 (or 5) notes higher (on the 12-note scale). To my understanding, based on my investigations of the .dsnd file format, at this highest tune, the sound is played at 44.1 KHz. The original sampled sound is at tune 0.
That means that a 2box sound with max tune of 5.0 is only sampled at about 33 KHz, and a sound with max tune of 4.0 at roughly 35 KHz. The higher the max tune, the more compressed the sound. This way precious flash space is saved so there is place for more sounds, but unfortunately at a cost of slightly diminished quality of the sounds.
It would be interesting to hear how the 2box sounds would sound "uncompressed", i.e. at "real" 44.1 KHz. I think we would hear an improvement, especially for snare sounds (which are mostly compressed to a tune of 5).
The ideal solution would be if the module could support a lossless compression like FLAC, but I do not know if there is enough computing power in the module. Otherwise perhaps in the future the module could support mp3 or similar for the songs; then many megabytes of flash memory would be freed up which then could be used to have a bit lower compression (and higher quality) of the rest of the sounds.
