I don't recall linking directly to the ISOs, so all links should be pointing to the Microsoft Vista RC1 download page. Which link isn't working?
As to the download time, it's not your imagination. First, the download is smaller...Vista Beta 2 (build 5384 x86) was 3,276,952KB while Vista RC1 (build 5600 x86) is 2,646,272KB. That's over half a GB they trimmed off the download. Also, download speeds are faster, in part because Microsoft dedicated more bandwidth to the downloads to handle the load.
Are these really the RC1 versions because I can't access them through the Microsoft Website only through your link. And for some strange reason the download seems faster and different then the beta 2 download.