From what I understand ( which my pre-health person told me), you first go to your professors and ask if they will submit it electronically. After confirming, you click that button that they will be doing it this way.
It is a new system so if it is faster or not, we won't know.... however there is less of a chance of AADSAS/schools losing your recommendations. That is a HUGE plus.
In addition, as soon as you list your LOR people, they will get an email, so make sure they know about this first, otherwise they might not know what to do.