The command line I used:
vs_Enterprise.exe --layout z:\VS2017_RTM --lang en-US
last lines of the console: ...
Download of 'https://go.microsoft.com/fwlink/?linkid=823168' succeeded using engine 'WebClient'
Download of 'https://go.microsoft.com/fwlink/?linkid=833503' succeeded using engine 'WebClient'
Download of 'https://go.microsoft.com/fwlink/?linkid=833501' succeeded using engine 'WebClient'
Download of 'https://download.microsoft.com/download/B/5/5/B55373E5-8948-41DF-B1D5-F60896104294/WinSdkInstall.ps1' succeeded using engine 'WebClient'
Download of 'https://go.microsoft.com/fwlink/?linkid=838828' succeeded using engine 'WebClient'
stats of the target directory so far: 2,631 Files, 1,005 Folders total 14,444,652,261 bytes
I previously got the offline download to complete with version RC1 in November 2016 but RC2 in Janurary 2017 always hung in the same spot. I didn't pursue RC2 troubleshooting since RTM would be available a month later and I hoped whatever problem with RC2 would be resolved in RTM.Well, it still doesn't work. Please let the MS team know that there's something about the offline download ("--layout" option) that's fragile and prone to hang. I don't believe it's an issue with overloaded servers because when I tried multiple times with RC2, it always hung on the exact same file whether it was morning/night/ weekday/weekend. I suspect the current problem is similar.
I took a screenshot of the hung process for RC2 in January and it seems to hang right after downloading WinSdkInstall.ps1 which is similar to RTM behavior:
RC2 hung in January: http://imgur.com/a/uwfoj
RTM hung in March (today): http://imgur.com/a/QxqC3