Do we even know if the SMC device is shipping yet? It was announced over six months ago at CES 2014 but often products don't ship for a very long time.
And even if it is shipping, and you can find someplace to buy it there is the issue of getting Rogers to provision it. And who knows if it works any better than the CGN3?
When you Google SMC D3G2408W most of the links are from CES in early Jan - and this thread even shows up on the first page of Google results. I am guessing that means that this product hasn't hit the field yet.