I have a client who has a R510 Unleashed, this client hasn't had any major problems over the years. We do regular updates and the none of the wireless clients have really had any issues on this site.
After updating from 220.127.116.11.246 to 18.104.22.168.234 they have had numerous problems getting disconnected multiple times during their video conferencing calls, their iOS devices reporting "The Wi-Fi network "XXXXXXXXX" does not appear to be connected to the internet. Do you want to temporarily use cellular data?"
This was rock solid for several years, one day after updating the client noticed poor performance and connectivity issues.