It really depends on a lot of things but especially how you have your tank set up as to what media you need. I don't use GFO unless I really need it (not very often) and I have a really really heavy bio load. My SPS don't like it at all. I find I get random burn marks on my sps and the corals don't grow as fast as if I only use the pads. Because of my natural approach setup for my tank that I use a little products\chemicals as possible in. I foster the tank to take care of most of my needs and with my large productive refugium the pads fit my needs just fine as GFO for my low levels are overkill. When picking phosphate or any media you need to pick what best suites your levels. If you have higher levels or they accumulate in your tank quickly GFO or other quick removal chemicals are fine. But if they are low and slow like mine are you will cause more issues then it is worth using GFO so you should use pads or other less aggressive removal options. As phosphate levels will go to low and you will cause SPS issues.