Just done e-Visas for two friends who are coming out in May. As people have said, relatively easy and quite quick. However, the Visa makes no reference to the Shengen rules and method of calculation from date of departure. People who don't use forums could very easily be caught out and be liable to a fine and perhaps a ban.
I wonder if they will have someone at the airport doing the input for the e-Visas for people who have not obtained prior to arrival - can you imagine the chaos if not.