Not the new spin, but I've been running cosmic installed on the standard gnome fedora 41 (now 42) for over two months now and I'm happy with it. Fedora just updated to alpha 7 so we'll see if it's fixed the minor issues I had. The bluetooth widget hasn't failed since that one time it did, will let the battery drain soon and see if it notifies on low battery, the file explorer searches upon typing now which is great and was the only real usability niggle I had relative to nautilus (prior version you had to click the magnifying glass first). My use case is heavily minimalist so YMMV, but the experience has been near-flawless.