I could tell you my several ideas for zombies, but the truth is, most of them will never be implented. However, I have THREE ideas that I feel all realistically could be implemented and could have a positive impact on the game.
1. When a player dies, (not when they go down, but when they actually die), instead of just vanishing, their downed body should spring up and become a zombie. The player would still be spectating and spawn in next round, but this way it's more realistic to the characteristics of zombies, which is that they are infectious in nature.
2. Out of all the perk ideas I have ever seen, I feel only this one would be a strong additon and be as balanced yet useful as the original 4 perks. The perk itself allows you twice the amount of time before you bleed out when you are down. This would be neccesary and helpful due to the increasing size of maps, which sometimes make it literally impossible to revive downed teammates. The side effect of this perk is that it allows you to use you primary while down.
3. My biggest beef with zombies is actually not anything in the game, but the peoole who play it. THEY ALWAYS LEAVE. Always. To prevent (or at least lower) this, they should bring back lobby leaderboards from bo1, but with a new stat- "resign rate", which tells you what percent of games they leave.
Tell me what you think below!