Hudson, Pfitz, Daniels, Running Wizard, Higdon etc. all have training plans that have been used with success by a lot of runners. What's the main difference between them?  Why pick one over another?  What are the advantages/disadvantages?   I gather that Higdon is most recommended for beginners as there's little speed work and the mileage is really low, but what about the rest?

Tomato, tomatoe. Whichever latest trend or book is hot. Comes down to finding/adapting to each individual, McMillan was the best for my last marathon PR. Jack Daniels for the shorter distances. But, its been years ago.

Still no magic pill, though if you could find the right doctor perhaps you wouldn't have to do as much work.

Define success? Couch to completing a run or medicore to a new PR or decent to BQ ?

Hudson, Pfitz, Daniels, Running Wizard, Higdon etc. all have training plans that have been used with success by a lot of runners. What's the main difference between them?  Why pick one over another?  What are the advantages/disadvantages?   I gather that Higdon is most recommended for beginners as there's little speed work and the mileage is really low, but what about the rest?

I can chime in regarding Higdon and Running Wizard. I used a Higdon 18-week intermediate plan for a Fall marathon last year, and am currently in my 22nd week of a 24-week Running Wizard marathon plan. I think you can see some distinct differences between the two plans if you look at my daily mileage plot over the last year: Running Wizard vs Higdon

For me, the Higdon plan had lower weekly mileage with fairly high mileage "spikes" on the weekends. There is a characteristic "3x20" series of runs (three 20-milers) near the end of the plan, followed by a taper. The Higdon plan seemed like a convenient plan for people who have a hard time fitting in runs of more than an hour during the week. If you look at the plot, my RW plan (starting in mid-January) has much higher weekly mileage, but it's more evenly spread out during the week, and the weekly long runs aren't nearly as high a percentage of the total weekly mileage as they are in the Higdon plan -- this distinction shows up pretty clearly in the plot. My longest scheduled "long run" was 17 miles in the RW plan, and that was back in week 10 of the plan. The RW plan progresses through a series of phases, each of which builds on the preceding phase.  I feel like I've really gained a lot of strength and a much better aerobic base using the RW plan. I'll have more data after my June 22 race to compare these two.

I know very little about the other plans.

I wrote up a detailed comparison between Hansons and Pfitzinger a few months ago that people seemed to like.

Good job! Thanks.

The `Hudson book is more about learning to design your own plan based on individual strengths and weaknesses. He does have some canned sample plans in the back that a lot of people use, but much of the book is focused on how to construct more tailored plans, and adapt them based on how you respond to the training, though he does suggest a framework for them.