As a note, you will find many CQRs for sale (or in the dumpster), avoid at all cost. They are the (by far) worst (yet popular) anchor ever produced
A genuine CQR is an acceptable anchor if a tad heavier than others for the same holding power. I would by no means say they are the worst anchors. Cheap knock-offs of CQR's are sometimes lousy anchors. I kept one for use as an Angel for a while--but it ended up in a dumpster eventually when I made a better one. For me the only acceptable copy of a genuine CQR is a Manson. I have used one of these without problems but it weighs over sixty pounds--and I have it shackled to 200 feet of 13mm chain and 400feet of 20mm nylon hard laid rode. My vessel weight about seven tons with stores and some water aboard.