I haven't tried these products - mostly because the premise of improved "clocking", "timing", and/or "less jitter" improving SQ doesn't seem likely given the error correction in the TCP protocol - as well as where these switches are to be installed (before the streamer/server).
In my experience, "noise" in the digital front end plumbing can have downstream effects on SQ, and I have had good results using products that aim to deal with that: linear power supplies, Gigafoil, ENO ethernet filter. FWIW, I have what I consider a decent streamer - the DCS Network Bridge.
Looking at a few of the audiophile switches mentioned here, most only market the improved timing, decreased jitter or "data integrity" as the stated benefit. A few do mention techniques to reduce clock and other "noise", and/or using improved external power supplies to that affect. I could see these possibly having a benefit.