I'm quite pleased with our reaction functions. Even when I react to another poster's reply, I will generally reply to it with another post. I like healthy discussions and that consists of people conversing with each other. If I "agree" to someone's comment, what did I agree with specifically? Sometimes shorter replies might not require a comment of agreement, but lengthier ones seem to warrant such replies to specifically state what I agreed with -- and perhaps what I didn't agree with.
Either way, I don't really think about the reaction functions. Sure, I use them, but I don't necessarily think about which ones we've got and which ones have gone away. I just use what we've got, and if none of the apply, I just simply like the post (therefore acknowledging it) and then simply reply to it and explain where I agree or disagree concerning the said post.
