What takes the longest in the server moves?

[CWeb Creative]

Ok so it seems like the restores take the longest but why is that when it seems in comparison that the backups take no time at all. I cant answer this because i have never worked with cpanel so i cant say anything about it. So i'd like to hear from someone who has dealt with this kind of thing before. I mean someone who has done this on a large scale eg 2k+ accts per server.