I got the speefil A2 with the SC adapter as well. Fit perfect and I have a garmin mount right in front. All nicely in line, but I had to adjust/cut the front straw so it wouldn't hit my face.
I tried to find a solution for the straw, ended up flipping for the (overpriced IMO) Speedfil cable retractor.
It's working out great though, so I guess money well spent...