The configuration of the Way Huge Electronics Fat Sandwich Harmonic Saturator allows for the user to have a serious amount of control over their sound. Not only are there a bunch of different parameters to work with, but most of the parameters have the capability to change the sound pretty drastically depending on which way you turn it. These parameters include those for volume, tone, distortion, presence, and resonance. The resonance is definitely a welcome addition here to the other more standard parameters, as it's possible to change the tone a good bit with this parameter in particular. I haven't seen a manual for this pedal so I can't speak to it's make up or helpfulness.
The tone of the Way Huge Electronics Fat Sandwich Harmonic Saturator is clearly the best part about the pedal. It's not the type of pedal that I would use if I had to choose one pedal to get all of my distortion or overdrive tones, but for what it does do, it's really an awesome sounding effect. You can get subtle overdrive or go all out with some heavy distortion or fuzz. It's got an extremely thick and well rounded tone overall, and I love having this amount of control. I used the pedal with a few guitars, but mostly a Fender Stratocaster plugged into a Fender Twin Reverb guitar amp for recording.
Way Huge Electronics is definitely one of the best out there when it comes to making interesting pedals with interesting pedals, and the Fat Sandwich Harmonic Saturator is no exception. It has a really great sound to it that can definitely be used for a variety of genres. The price for this pedal and for Way Huge Electronics pedals in general isn't going to be the cheapest, but considering you're getting a top tier pedal with a perfect build, I can't really complain too much about it. If you're looking for something a bit more traditional, I'd check out the Camel Toe Triple Overdrive, bu the Fat Sandwich is an awesome pedal that's worth the time to try out.