DO WANT.
More seriously, I like Quick Reply functions essentially because they do not force me to load a new screen in order to post. A few ways this is helpful:
1. If the computer is having problems, it cuts down on the number of shit I need to load.
2. It makes it faster & easier to post, which is helpful for when the topic is moving quickly, or I am otherwise in a hurry.
3. Perhaps its most useful function is being able to type a post while looking at the current version of the page. Useful if, for instance, I'm responding to an embedded video.