Many of my ebooks are anywhere from 50 to 350 Mb. That adds up when you want to load many of them. The downside of course is that you need a good Net connection

Many of my ebooks are anywhere from 50 to 350 Mb. That adds up when you want to load many of them. The downside of course is that you need a good Net connection, unless the Calibre Content Server can be configured to do some kind of 'trimming', while serving the ebooks over the wire. Also a content server mitigates you having to manage and synchronise your ebooks in multiple places. You only need to manage one library. Although I guess any sync application can work just as well for this.