I have mine set for 2200 Kbytes/Sec and have never had any problems. That's what it was set for when I had 4Ks and when our system was upgraded to all 5Ks I never changed it. The fastest speeds I get are typically more like 1.3 MB/sec however, compared to the 2.3 MB/sec I used to get with the 4Ks. These speeds are with the units powered off and no streaming, of course.
Tim