I got good results with crossfit (dropped 40 pounds, now I'm "athletic" -- I'd never have imagined I could do 20 pullups before), but I'd do it even if it was only average, because it doesn't bore me.
Running? Unpleasant and boring. Weight lifting? Boring disciplinarian bullcrap ...
Crossfit? I check the website, burst out laughing, grit my teeth, and then do something that seems almost impossible yet takes 30 minutes or less. Awesome.
Look at the training regimes for Olympic-class athletes in any given sport... they're a pretty good guide, considering the incentives involved.
There is solid data, described in the article and found elsewhere on the web that short, intense fitness sessions where most of your work anaerobically will in fact prepare you for aerobic activities. CrossFit is the empirical proof of that.