Downloading 700GB P2P, I guess that would take weeks or even months.
No. Please do not post when you don't know what you're talking about. The bottleneck currently is not, and is likely not going to be the download speed.
it would only take 9 hours to download 700GB today on a 200mb connection (fibre)
You're assuming that the 8 nodes that you're connected to can provide you with a full speed download at all times for that speed. As mentioned above, the bottleneck is going to be the validation time.