It only took me about 20 minutes. LOVE the new folders! I can actually fit everything on the screen now and don't have to scroll down that much! Loving it!
about an hour with lumia 920 over wifi from start to finish. But I think it also depends on how much data and apps are on your phone (the migrating data part I guess)
It took me 10 min to download and prepare and another 50 to migrate (got only 1.5Gb free on my L1020). Although this seems too much, it seemed much shorter than previous updates... One thing I noticed (this time and not before), was that few (many initially) applications were listed/labeled as "Installing" once the process was complete and I could login to WP8.1.1
Love the new folder feature. Still no BTLE without Cyan...
Mine took about 40 to 60 minutes to download, I know because I was watching Futurama and then the next program was The simpsons, so that's about 1 hour, and it still is migrating my data, but this means everything went alright, right?