In Volume 1 of The Confidential Guide to Golf Courses, Tom Doak published that.

“Just inland from the famed Royal Troon championship links, their back-up course has a famous pedigree, but little in the way of memorable terrain. Dr. MacKenzie was pleased at the frustrated reactions of the professionals when the course first opened, but he would not so happy that the course has remained a distant second fiddle.“

The Portland Course at Royal Troon Golf Club received a score of 4 out of 10 from Tom Doak and a score of 3 out of 10 from one of his co-authors.