MTF is said to have changed significantly sometime during the 70's (so I am told by a relatively believeable source) when Indica genetics made their way to Alaska. Before that, it had been strictly NorCal sativa genetics. Depending on the time when your particular cut originated, you may find that you have an indica-leaning or sativa-leaning version.
I hate to put the label the 'true' MTF on anything. Instead, I consider MTF to be a CLASS of Alaskan genetics. I know plenty of people will argue that point with me, but the basic truth is that localized and somewhat isolated growing communities each have a basic line that can be traced to the same origins.
I'm not an authority on this by any stretch, but if you read around enough, and talk to enough people, you should come to a similar conclusion.