1. If you have a brief discussion you can do 2 ways with replays or with a quote
quote is not necessary if you're continuing discussion of the last post in a thread
people will understand it, just like reading a written conversation
2. If the discussion is very long almost half tread or one tread, don't comment with the quote, because later it will look like spam. Better with replay.
if you need to use quote, do it effectively by selecting the necessary part only
only quote the related content that you want to respond to and remove the rest
something like what I've done here quoting and responding to your post