MTG Salvation

4 mana for a counterspell that only hits cmc <5? No thank you, I’ll stick to Rewind

Mana Leak is better against cards that cheat on mana like Delve cards (or Tron finishers) but Prohibit being a "hard" counter can be better when the opponent has mana to spare so it is much better later in the game.
Countering any spell up to 4-mana gets most cards played in Modern which is very good imho.

I'm definetly going to try it out in my control decks over Mana Leak and see how it goes.

Yeah, but I’d take a mana leak over this turn 2 any day. My big problem with this is that it’s basically dead late-game against most decks. At that point, I’d say really the only thing I’d use it for is countering counterspells

You can play this on turn 2 and 3 though unlike Rewind (or Cryptic Command).
It competes with: Mana Leak, Remand (or Logic Knot) rather than Rewind.