This is my crummy little primrose from the big box store. It has impressed me with repeated blooming throughout the summer!
The interesting thing about some Primula you buy in nurseries, particularly the pretty little ruffled, semi-double ones is that they usually rebloom as singles. It be interesting to see a picture of next year's flowers to see if they look as pretty.
My little grocery store primula continues to bloom in my unheated greenhouse, though I think you're right - it seems to be getting a flatter profile