It's not hard at all to use the Vox Satchurator, as the parameters are ones that you'll find on virtually every distortion pedal. There are a few added features, but nothing that isn't more or less self explanatory. The pedal has three knobs for gain, tone, and volume, as well as two buttons for engaging the distortion and another labeled 'more' for adding, you guessed it, more volume to your sound. The pedal also has a pad switch for helping to compensate level wise to match pedals put in front of the chain. I haven't had a need to look at the manual for this pedal, so I can't speak to it's worth.
The Vox Satchurator is a pretty powerful pedal as it's got a huge sound. You can get a nice array of tones with this pedal, all of which are quite thick and huge sounding. Of course they say that the pedal is supposed to give you a sound like Joe Satriani's, but realistically, that's not possible unless you're Satriani himself. Having said this, I can certainly see the resemblance between this pedal and Joe's sound, as it's a very rich distortion with a nice amount of low end presence, much like Satriani's signature sound...
The Vox Satchurator is definitely a pedal worth knowing about and trying, whether you're a Joe Satriani fan or not. Certainly fans of Satriani will take a liking to this pedal more than others, but it's a great overall pedal that can be useful regardless of your personal opinion on Joe Satriani. It's probably a bit overpriced, but still not too bad considering the great sound. Definitely a must try for Satriani fans and beyond!