When Champions first came out I've had really bad stutters during combat. At first I thought it was just time to update drivers. Did so, and no change. After a little bit I started to realize that the issue was only occurring on my mesmer.
Well turns out, that on a mesmer, with seraph wing backpiece. As soon as I create too many clones, my fps stutters to freezing every 1-2 seconds while in combat. Its such a weird issue since me and my wife have nearly identical PC specs, and my performance takes a huge hit when my mesmer has this backpiece on. I've also made a video that shows the issues