I can report that having 100 Mbit at home is a good thing. I know, who would have guessed? The raw speed makes an enormous difference. For instance a couple of days ago I installed Skyrim. 10 GB of download. On my old DSL that would have been 4 hours, something to schedule overnight. Now it’s less than 20 minutes. Also means I can stream an HD movie without worrying whether something else using the link will ruin the playback.
But the best thing is having so much capacity greatly simplifies the router. I used to go to great lengths to have QoS routing. Right now I’m experimenting with not bothering at all, it’s completely disabled. I don’t notice any problems even when running a full speed BitTorrent both up and down.
Part of the advantage is my Internet is now faster than a lot of the backbone, so “full speed” for the average site won’t saturate my link. I also think it matters that the packets are relatively smaller. On my shitty 1Mbit link a 1500 byte packet is 12ms wide. Even with perfect packet scheduling there’s going to be uninterruptible 12ms delays sometimes. With this good link that time goes down to 0.12ms, making it much easier to share the link between multiple applications.