Plusnet's traffic management system has been taught the traffic types of basically every game (and if it doesn't know one, you can use wireshark to send them some of the packets & they'll add it).

Bottom line - since games don't encrypt their traffic (why bother?), their packet inspection kit can identify it and give it a priority boost. Stuff it can't identify, it does indeed dial down in speed.

Bottom line though is that gaming will be nice and fast, you'll have a solid speed overnight to transfer large files. Only consideration is how much iplayer your partner watches - whether it'll nip at the heels of the 40GB limit. You could, if organised, download shows overnight if that would suit your timetable.

MrSaffron is right. I've got dual screens & have a bandwidth monitor on the other. When I've been hosting a 4-way skype call & hosting a left4dead2 server, my upstream has been at most 40-50KB/sec (so, 0.5mbit give or take).

To not host skype and to participate on another server, my upstream falls to 5-10KB/sec. So as long as the ping times are low, any throttling that DOES occur will largely go un-noticed