I am using them on my 180. I set it up with them to start. I am using the BRS reactor currently and it works well. I started with a phosban reactor modded to run pellets, but it seemed to clog rather quickly, so I switched reactors. I installed a Octopus reactor for a customer and I like it really well.
I have done two water changes since last Novemder when I set up the tank, and it is awesome...0 phosphates, 0-5 nitrates. I do dose the tank with trace elements from time to time and alk, and Ca.
I dont think I will run a tank without them in the future. Just my personal preference. HTH