One man who knows more about Snoke than the rest of us (we assume) is Andy Serkis, who provides the motion capture for the digital creation as well as the voice of the character.
The actor says that there is a significant difference between the two, specifically, Palpatine isn’t nearly as dark as Snoke.
People made a lot of comparisons between the original Star Wars trilogy and The Force Awakens, and one of those comparisons was between Emperor Palpatine and Supreme Leader Snoke, but does the comparison really fit?