Very robust sound generator. I used to use a free flash-based program called BFXR, but I was looking for something that could generate more than just 8-bit sound effects, and this matches that perfectly, along with being able to record things with your microphone and build upon that as well.

However, there are a few minor drawbacks I've noticed within less than an hour of using it. 

• The GUI cannot be reorganized, resized, or adjusted in any way.
• The parameter sliders, while offering incremental adjustments with both mouse scroll wheel and keyboard arrows, don't allow for direct value inputs. If I wanted to add a high-pass filter at a specific value, I would have to click the slider as close as I could get, and then adjust the rest of the way with the scroll wheel and arrow keys, instead of just typing the exact frequency I want.
• If "auto-play" is enabled, using arrow keys while doing the above action will result in it playing every time a value is incremented by one. This caused the program to lock up, and I had to restart.
• There is no undo/redo functionality, nor is there any way to revert changes. This was one of my favorite features about BFXR, because if I clicked "Mutate" and I didn't like that particular mutation, I could always revert back to the previous sound. I think SDX could benefit greatly from this feature.
• Sound effects are saved in .webm format. This one isn't too big of a deal, but I prefer saving in wav, mp3, flac, or ogg.