Is it me or has Sub Zero's slide always been as abusive as it is online? About the only thing I can counter it with is Nightwolf's shoulder ram. Is the lag demon killing me from countering this with other characters or has it always been as fast a recovery?
You want to block it when it's very close to you, and try to release block the instant it touches you, you even have to do this offline. It's not unpunishable, but when you play, you get into a groove where you know exactly how to counter it. You want to make sure you get a F+Run+Attack out on it. I use the slide a lot, but often times when someone is jumping, and very often I'll hit it so they land on it, and it flips them the opposite direction. It's all intentional.
Classic Sub's slide is beast. And very useful. Freeze, Jump Kick Starter, Dail-a-combo, aa Jump Kick, Slide=Easy 45% damage combo. Other than that I find it works very well against Scorpion and the Smokes becase right after they spear you slide. It works wonders and gets me out of jams.