Just heard about this.Hopefully its not old news:
I wonder when the r7/a7 switchover will happen and how different they really are in terms of speed, price point etc.... Apparently Hoosier hasnt said much about them yet

Hoosier SM7 Official for 2014 - Spec Miata (SM) - Mazda Racers

 

Local SM guys were clued in late this summer, they all knew to "expect a tire change" and were selling scrubs unusually cheap

From your link:

J. Drago(SM champ) after the test day at Roebling Road:
"My observations..
-What I saw was a tire that was very comparable to the SM6.
-Overall lap times were thought to be faster, in actuality they were a little slower.
- The drivers all commented that the tires were much easier to drive ( which is suprising as the SM6 is already very easy to drive)
- wear was not an issue in either tire and I don't rememeber seeing much difference in wear in the tires
-there was no "magic lap" in the SM7 like there is in the SM6 (usually lap 2) We did not see that in SM7
-The drop of SM7 sticker was comparable to that of the SM6
-The SM7 is not supposed to grain( neither grained in test, but we were assured the Sm7 will not grain like Sm6 does at certain tracks ( COTA, Hallet, Mid Ohio)
- drivers all felt if the new tires read SM6 instead of SM7, few if any would notice any difference.
-this is not a new compound, this is what is being run in Grand am now
-also look for a regional contingency to be announced"