I went to the Spot dealer over the weekend and I had a test ride of both the Ajax and the Acme. Very nice rides and yes it is quiet, however I easily maxed out on 8 on the Ajax, there's a bit more speed with the 11. Also, the brushed alu on the Acme is a lot nicer than I thought, it's not shiny at all like on the photos and you can't chip the paint!
... I'm almost sold