What I noted between the two mainsails I had was
1) the head on the newer sail wasn't as wide as the older sail
2) the leech down near batten 5 & 6 was about 2" different

Also, the battens for one sail didn't fit the same way in the newer sail. I attributed this primarily to stretching. I had to cut the top battens about an inch on the new sail to keep it from sticking out so far...

I figure #279 sail was probably a bit different as well, as that was the earlier generation sail. I think the same was true with the three spinnakers I had (the shoulders looked different, even before they were heavily used - probably just my uneducated eye)

It's good to know that they're computer cut and good quality control.

And whatever the sail cut was or was not, the sail's effect on my performance was negligable compared to my sailing ability...