Elos > most. I'm currently rocking an Elos NS1000 skimmer. It's a beast when it's dialed in and also purchased all their test kits off RC for 50 bucks shipped! Couldn't pass it up.
Oh no it was fine before but I've had def results from elos. I use amminos, omega,stront,cal,mag,iodine,filtra m,and fish food and rbc's to feed corals! Phanominal results. They're products are so concentrated it makes doseing easy on our large water volume system. We have about 300 gal total.