We have been using Veeam BDR for many years, CC for less than a year and just started to beta/test the Veeam agent for windows.
We also have run into issues where a single device will consume the entire bandwidth of a connection and/or consume all of the devices CPU resources.
Other solutions we have (and currently) use, typically have a bandwidth limitation feature that can be set, for example to 512Kbps at the agent level (reduces slow connection issues). They also have options to limit the amount of CPU in use or similar types of settings to manage CPU resources.
Being able to limit CPU usage for example to no more than 50% also comes in handy(reduces slow computer response issues).
Will the agent for windows have these settings? (I suggest that it does)
A more advanced setting (that I have never seen before in a backup agent but I think may be useful) is to be able to set multiple bandwidth limiting settings, each with different values based on the public IP of the devices connection.
1) If public IP is x.x.x.x then limit bandwidth to 512kbps
2) If public IP is y.y.y.y then limit bandwidth to 2Mbps
3) If public IP is z.z.z.z then do not limit bandwidth
4) If public IP is not any of the above (default) then limit bandwidth to 1Mbps
The advanced bandwith throttling option is not necessary, however, basic CPU and bandwidth throttling are in our experience.