I own a Trigger Systems Crystal Crys30S and have no complaints. Well built and well designed. Im pretty sure the Emeralds are newer on the market so I don't think too many people own them. Cant go wrong with a Trigger Systems sump- IMO.
I have the Emerald 26 under my DSA 65 and I love it. It's very well built and growing cheato and pods like crazy in the fuge section for my Mandarin. I was only slightly challenge to find a skimmer that fit in the skimmer section. I would buy again if in need for a "small" sump.
Thanks for the feed back! I'm somewhat interested in removing the filter sock and running filter floss with the dripping tray. Are you just running the sock or spoung? I also like the fact it has a section I can put carbon/media.