On my current dude, I kept the workout ALWAYS within .1 of the recommendation.
I had NO increases, until I hit 32. Between 32 and 35 I increased contact 10, power 20 and gap 30. At 37, sadly, I started the year already down a couple points C, P and G. BOOK TIME!
Also, my energy never went below 68 at any point in my career. And that was only when I was 35 and had a contact increase and I wanted to fill it out so I added a Bat practice. It was usually 70-72.
But to comment on the original post, I think Wolf has it right ( I think that's the second time I've said that in a week? anyway

...). I think EYE is important. I even think it says so when you make your character, it will help your average. I had 40 my entire career. When I was 34, I had 70 contact, +5 gloves and WOnderboy (+ 16 contact) and only hit .285. After my contact increase to 80, with W-Boy and +9 gloves, I hit .283. I can't help but think EYE would increase that. It just doesn't make sense otherwise...