I don't use lollipops. I use the tiny little button gauges on my deco bottles. My reasoning is that I don't want to look down and and mistake a deco bottle spg for my back gas. Granted, if you have two/three gauges near each other, it should be easy to figure out which one is which (e.g. the two 3k ones should be the deco bottles and the one that reads 2.7k is likely your back gas). But add some task loading and a little narcosis and I'm not 100% confident that I would always make the correct assessment in a quick glance.
I plan my deco gases for the dive I'm doing; I should have plenty in reserve, such that looking at a gauge on my deco bottles isn't an absolute necessity. On a recent dive, I lost some of my 50% O2 deco gas. I knew I had lost gas, but not how much. During deco, I just swung the 50% bottle around and verified on the button gauge that I was way lower than planned, due to the lost gas. I had two contingencies in place for this lost gas and all worked out fine. The button gauge just gave me a heads up to plan for my contingencies before the tank went dry.
With that said, I'm not a cave diver. Depending on the kind of diving you do, YMMV.