This pedal had a lot of bad reviews, and in a way if you expected a convenient multieffect with analog fuzz, reverb and trem that would replace 3 basic pedals, I understand that you would be disappointed. But if you accept its limitations and explore its specificities there is a lot you can get from this pedal.
You could just be happy with the 2 reverbs and the 2 fuzzes. You can't change the fuzz settings but the tonality options provide many sounds. Put everything on 11 and you get a thundering sound that would require a heap of pedals to reach otherwise. Tremolo is basic, and the pitch shifter has obvious flaws that properly used can bring unique sounds - I use it for detuning or 100% high pitch.
Being cheap and obviously upgradable, the Holy Stain calls for mods to give extra controls to the reverb and the fuzz, and tweak the chip to get the flanger that is hidden in it.