I have Chloramines so Prime is my dechloriminator of choice. It's concentrated so I use less and it does a fine job. I used to use Amquel but I will never buy it again unless Prime goes off the market... Oh please, Seachem, keep it on the market!
I use the minimum necessary. My water has chlorine-only most of the time, and as I age water with heating and aeration, that alone is normally enough. However, my utility does at times add chloramines, so I do test. If chloramines are present, I use Prime.