I bought the FD5 recently as well and I am very positively surprised. Built quality, extras and foremost sound are excellent. For me comfort as well ( I use the smaller nozzle with the smallest tips, the Moondrop Blessing 2 did hurt my ear channel, so I sold it, too big for me). I use EQ and really wonder if there is any substantial upgrade in sound around with a much more expensive IEM? Would be willing to invest, but only if it really sounded better (resolution, soundstage, transients, the like, since FR and lack of distortion seem already at best).
Edit. I think it is really amazing what you can get nowadays for your money, about $250 at aliexpress for the FD5 (the appr. $200 7Hz timeless is also extremely good, living up to the hype), about $120 for the Hidizs S9 Pro dongle and, assuming you already have a cell phone and a Macbook with SoundSource EQ, $10 a month for Qobuz and you are already close to audiophile heaven.