I don't have any 70.3 experience, but it's on deck for next year. Like you I have been using the 80/20 book and have been happy with it, but I've been eyeing some other programs for next year. I'm looking at EndureIQ (Dan Plews), Dan Lorang plans, and Jim Vance plans on Today's Plan,

IMO, the most useful thing in those plans are the recovery weeks, that self-coached people tend to neglect, until they burn-out. To answer your question, I like the structure of Phil Mosley plans; but 80/20 are quite good too

I just got done with a Phil Mosely plan - it's very generic, but the structure was what I needed. I did see gains in my endurance due to the regular training, but was lacking in some of the excitement due to the workouts being very similar every week.

They do advertise contact with the coaches pretty heavily, which was my biggest criticism of their whole program. They cannot look at your Training Peaks account, so you can only get very general answers to your questions through their ticket system. It just felt very underwhelming as far as coaching contact goes.

i really liked and succeeded with the 80/20 plans. I did a little self-coaching 20 years ago for a some olympics but otherwise have nothing else to compare to.

I didnt have to think about my workouts, i just did what the plan said. the bike computer integration for workouts was really nice.

midweek workouts were reasonable for people who work and have families.

using it over the course of 2 seasons and 4 total races, i kept getting better/fitter. my 4th race was a much harder course and at the end i was almost as fast (90 seconds) as my 3rd race.

i'd use it again without hesitation.