Having been through both: AFROTC field training is about half the length of USAF enlisted basic. In fairness to the cadets, they attend training throughout their college years before and after Field Traning - the whole experience is more of a slow long ramp of goofy BS that tries one's patience in ways most enlisted troops won't quite comprehend until they're an experienced NCO. It's also much easier to "just be a number" and muddle through enlisted BMT. Try that in officer training, and you'll be ranked bottom of the class with limited career options.

In terms of physical exertion, enlisted BMT is a bit more intense. Job-specific training might be much more intense, for the handful of AFSCs that see ground combat.