"This is a tasty cookie."
Translation:זאת עוגייה טעימה!
So, what is the difference between using זו and זאת? Do people use זאת more in colloquial conversation?
historically, זו is probably from Aramaic, while זאת is biblical. Neither is more formal of high-class than the other. Note that זו is pronounced "zo" - there's a holam there.
There is another word that's spelled the same, but pronounced "zoo" with a shuruq. That has a different meaning, similar to אשר. This word is not particularly high-class, but is pretty rare in modern usage.
Of course, not everybody pronounces the word correctly according to meaning, so you might hear "zoo" when meaning "zo". That is why I prefer to use זאת.
Yes - I think זאת is more common colloquially, but both are used.. it's not like it would seem out of place to use זו.