Just to add some actual stats to eschwartz's F.U.D., as it happens I just added my 10 newest reads to a Kobo Aura H2O via calibre/USB. It took 50secs for the Kobo to process them. I believe Kobos
are slower than some other devices at processing new books but I can live with 5secs/book ... but then again I'm retired I have plenty of spare time