It was the good link. Here's the key point: "On average, subjective evaluation showed that students found transactions harder to use than coarse-grain locks, b

It was the good link. Here's the key point: "On average, subjective evaluation showed that students found transactions harder to use than coarse-grain locks, but slightly easier to use than fine-grained locks. Detailed examination of synchronization errors in the students’ code tells a rather different story. Overwhelmingly, the number and types of programming errors the students made was much lower for transactions than for locks. On a similar programming problem, over 70% of students made errors with fine-grained locking, while less than 10% made errors with transactions." Transaction are felt as being of average difficulty, but they in fact spur far less errors. I bet we could find the same kind of bad judgement with "map" higher order functions vs "for" loops.