I've used Rollei, Moersch SE5, Champion and Arista liquid. I found Rollei and Moersch (without additives) to be similar. Champion and Arista are also similar and, unfortunately, contain formaldahyde. I like them for Slavich paper, but have pretty much stuck to Rollei otherwise. Both Rollei and Moersch are formalhyde-free as far as I know. I've heard that Fotospeed and Rollei are the same, but I have no direct experience to confirm that.