I think both companies are great and I try to support both when I can. While QMX's output has dropped significantly, they did great work for a while. FanSets seems to treasure their Trek license and I've been really impressed by the quality of the items I've purchased from them but neither company is in the business of producing screen-accurate replicas.
For example, QMX's Voyager badge is very close to the right size and shape but it is highly idealized. The props on the 90s-era shows were resin sprayed with automotive paint and the original molds were sculpted by hand. If I recall, QMX had access to the original prop mold for the GEN/DS9/VOY badge but their final product was machined metal and super shiny. Still a lovely piece. I don't have a FanSets Voyager badge but from the pictures, the shape is pretty off but they seem to have nailed a more accurate color scheme.
All that said, FanSets seems to be moving toward releasing more accurate deltas. Their Picard badge is made beautifully but still has some significant differences from the screen-used props. Still happy to have it in my collection. Their new Pike badge looks
really good and I pre-ordered the moment I saw the TrekCore article. It feels like they're pivoting to fill the QMX void and the quality (and accuracy) of their badge offerings is improving rapidly.
Bottom line? You asked about quality, not screen accuracy. In my opinion, both companies produce high-quality items for the price. I do collect screen-accurate prop replicas but have been happy with everything I've purchased from QMX and FanSets as well. I suppose it's all about the flavor you're looking for
