Hi @localstarlight, this is something that's being investigated right now. It seems to be an issue with our CDN (content delivery network), not software based.
Did you continue to download and see any change in speed? I've been doing testing myself at home and while downloads did occasionally start slow, they usually sped up to 'normal' within a few minutes. Can you let me know?
Also, although this is a frustratingly random suggestion, logging in/out should reset your CDN connection and therefore may give you an immediately noticeable speed bump... but it's not a guarantee. As I said, it's being looked into. Do let me know if you see a gradual increase over time, as I mentioned.
This is happening to me as well. Got a cyberpowerpc with securit antivirus and when attempting to download 2 games that came with the htc vive, the dowloads crawl by and then stop at 50-60%. Steam was slow too, so I figured it was the isp or antivirus... after a speed test and a little testing around, I do not think those are the issue.