So with my latest unposted big mac being too close to the show for my purposes I decided to try to figure out why the sudden jump in quality. So I counted how many points my no curve pics are made of. First big mac: 128, second big mac, 139 but also better placed lines and current big mac: 235 points. A massive jump in the number of points used can make all my straight lines shorter and more curve like when put together.
On the other hand points used are not everything, can't directly compare different characters, for example my applejack pic has 346 points and does not look as good, a lot of points used for her hat and I've yet to get back and clean it up.