Well, I wonder about slavishly following any training regimine.

Those things can be good for guides. But I always do better doing what I feel like as long as I get a decent blend of different training in.

Some people do best following plans very closely and others do better with a bit more flexibility. It depends on how you are mentally wired, I guess.

With aerobic base vs speedwork, I believe that it is important to get the aerobic base. But there is room for speedwork. I think this is especially true if you enjoy the speedwork. If doing some speedwork keeps you focused and motivated then it is probably not smart to drop it. Any training plan that you follow is going to be a whole bunch better than the ideal plan that you can not get motivated to follow.