The "Russian Mod" is the vanilla version with one more girl added, Daphne Greengrass, a Slytherin.
There are about 4 scenes with her and it ends with her being nude I think, nothing more, nothing less.
In comparison, Silver has Luna with, already, more content and scenes. There is also cho chang with about as much content as Daphne. Daphne is not in Silver though.
There are the same amount of base clothing items for Hermione, although, "Silver" has a cheat window that has a ton of more clothing items for her. There are also a ton of costumes you can dress her in and even use them during scenes.
More Hermione favours have been added to "Silver" while the other doesn't have any new ones.
You can make Hermione turn around to look at her naked ass, make her wear butt plugs in school, Scenes with Hermione and Luna, and so on.
There are also Potions you can give her in "Silver" that trigger events and scenes or change her body.
Basically the main difference between the two is that "Silver" will have lots more content being added consistently while "Russian Mod" has been discontinued.