Mentzer argued that 99% of people have never actually trained to failure. A digital PDF with analytics proves or disproves this. If your failure ratio is below 80%, you are not doing Heavy Duty. That is better data than any journal provides.
A "better" journal entry includes more than just the weight and reps. Every entry should track: Mike Mentzer's Heavy Duty Workout: The Ultimate Guide mike mentzer heavy duty journal pdf better