I've not tried link but isn't the 100m connection a bottleneck for say 4k? 12mbps isn't exactly high for a 4k stream.If anything, you might get more consistent performance as the link is designed purely for streaming and won't have other processes running.
If you are talking about the client I fully endorse the link box.
I can just walk over to my TV, picked up the steam controller and boot the main PC from there. The gaming PC, which is in the dining room boots up, auto launches steam and as the monitor is off you'd not think I even had a gaming PC.
Yes I have my gaming PC auto logon, then to auto launch steam. The Steam link starts this process via the Wake on LAN. I'd not considered any insecurities. It's just a PC in the corner which I can stand up to see if needed.How have you set this up?