The only time I've used counterspelling is in hypothetical fights. Four example, if I'm plotting out whether X level characters defeat an N type dragon, counterspelling helps because keeps a dragon's "I win" spells from going off, and simplies the battle by reducing the # of spells and character actions. Similarly, a higher level party might use counterspells to keep a foe from equalizing a magical advantage. A fully buffed party going against a flat footed one can afford to counterspell since it will keep them from throwing up their mass haste, or casting some dispels to remove the advantage.
I might have seen it used once in play, but I'm not certain.