CF Rest Days.
Here's my take on damn near everything. I call it my "80% Doctrine."
I don't believe you (but more appropriately I) can do everything to 100% without another area suffering to a degree. For me, this applies to everything from schooling to workouts to nutrition. If I obsess over sticking to 3 days on, 1 day off for WODs (which is easy to do), I'm not doing my body and sanity justice. In the way of intake (nutrition), if I weigh my food perfectly without taking a cheat meal, I'll go crazy. And in the way of relationships, fun, work and schooling, you can see where the doctrine applies as well.
Imagine you have 0-100 level bars (like in the Sims). Not all can be tanked out at 100% for an extended period of time. But the 80% level seems to work out the best without seriously jeopardizing the levels of the other (and equally important) areas.
I do make exceptions for competitions, tests, relationship lulls, etc. For a short period of time, it is definitely possible to max out on all to get maximum performance and happiness right before a big event. But keeping those levels at a 100% for a long time - say, more than a few weeks - doesn't work well for me. I also do make an exception for WODs. For that very, very short duration (20 min or less) I hit it as hard as I can.
How this applies to CrossFit, specifically: Most of the talented CF athletes are well-rounded. Compared to pro-level olympic lifters, runners, and gymnasts, they're decent. But across those modal domains, as well as the time domains, they are the best in the sport of fitness. If one only oly-lifts all the time, their 5K run will most likely be timed using a sundial. As well, if a person spends all of his or her time doing "Cindy" or "Tabata Something Else," their max deadlift may have to be measured in laundry baskets. All of this can be simplified for the kool-aid drinkers into "work capacity across broad time and modal domains."
80% Doctrine: Do everything to about 80% of your capacity. Seems to work for me ... or perhaps I'm just making excuses for not accurately measuring my fat, eating string cheese occasionally, and having beer and Ben & Jerry's once a week. How about "life capacity across broad educational, wellness, and emotional domains?" (Maybe that needs some work...)
Your thoughts are very welcome.