Mid screen I would always advise going for the ground freeze, near the corner the regular freeze depending on the character. There's a timing you can practice for glitch cancling the ground freeze off 2 HPs so that if you don't get it on the 2, you'll still get the 1 into a combo. aaHPHP, gcGround Freeze, HKS, 4 hit pop up, deep JK, HK = 10 hits 62%, works on Male Ninjas teleports, Stryker's Baton Dash. Vs Kung's Dive Kick, I would suggest attempting the ground freeze to relaunch infinite everytime because he is VERY easy for Sub to relaunch. You should have no trouble ending virtually any round off one bad Dive Kick if you practice it a bit, but even still at least a 62% combo is easily possible with one relaunch.
Depending on how close you are to the corner and the opponent, you might be able to get better damage with the air freeze since there will be no damage protection. Also remember if your opponent is too close to the corner you cannot do the ground freeze at all. I've see some players attempt it similarly to seeing players go for a Force Ball with Reptile after JPS, 3 hit pop up (results in standing HPs or Acid Spit). aaHP even vs a jumping attack with C Sub is golden. Use it often. Don't forget that you have the option of the cross up JPS during the Ground Freeze. If you are in the corner and get a free aa situation, do aaHP, ground freeze, cross up JPS and combo a juggle into the corner rather than juggle them out of the corner with something half as damaging. A similar error I see made with Kabal. Free spin situation when Kabal winds up in the corner, and then they just do his 5 hit combo, JK, AFB, no starter, not even thinking to push the spin and cross up to corner juggle resulting in up to 2.5x more damage.