Red sea does have a bad rep and I dont use my kit other than to hold my other test kits up.
API is what I mainly use for all my tests.
I believe I have a seachem test as well. If thats the one with the yellow disks for ammonia, then thats the one. It is more of a mini chem test kit and I dont want to take all those steps.
Hardest part for it all for me is to see the color differences. I have to ask for my wife's opinion to see if we are seeing the same color.