TvT only against mech. Against marine/tank, MMM gets shat on hard, no one does it anymore.
TvZ is extremely good against ling/festor. The fewer banes the better. Here the medivac count is key, a huge medivac count means Zerg units will hardly get to do any damage. Unless it's a baneling of course. The key of this strategy is to be extremely greedy and spot on with your macro, your units aren't as resource efficient as using tanks but they can still be really strong.
Even the smallest donations help keep sc2sea running! All donations go towards helping our site run including our monthly server hosting fees and sc2sea sponsored community tournaments we host. Find out more here.