Since all require a color judgment, I go with the test strips for ease of use. Once established the tank will rarely have nitrite if filtered correctly so I don't stock a separate kit for that. Kits, whether liquid or strips do get old and need to be replaced. That further drives me to the Jungle 5-in-1 strips as I test often and it gives the full readings of nitrate which is the one I watch most and then if there is a mess up that gives me nitrite readings it will tip me off to them without any extra effort. For me it is a question of doing the test because it is easy but maybe the results a .2 off from true which gives me no heartache or maybe not doing the test because it is a pain and then the fish get funky before I get the proper true reading. My eyes are not reliable enough judging colors to worry about a small amount of fault in the test kit.