lol...thats funny.
My answer was focused on the fact that you already had a controller. I was saying that you dont really need to BUY another, $200 controller to 'eek' out a few percent of efficiency. If you had neither controller, and you had a higher voltage panel, or were going to be running 2 panels in series, then yes, buy an MPPT controller.
Now, I have a question for you, poot (aka gimmytree on the other forum)...
If you consider Will Prowse to be the expert, why do you even bother asking the same questions on both of these forums, over and over?
All of us, everyone who has been trying to help you, myself, HDR, Jim in Denver, Sternwake, Frater, geogentry, gypsy freedom, and many others, have been putting in a LOT of effort to help you. Most of us have been working with batteries and solar panels and controllers since before Will was born. Many of us, myself included, have a solid background in electronics.
If you need help with this, thats fine, we will help you. But if all you are trying to do is to compare our combined decades of knowledge and experience with some young kid on youtube (who by the way, appeared here a couple years ago and was not giving good advice) then you are wasting time, both yours and ours.
I hope you figure this out. I really do.