I used to use a combo M2M / press for my D3 team, but I abandoned it a few seasons back and went to straight M2M. Some pros and cons I see of a man / press combo:
Pros:
- Flexibility vs one-dimensional opponents. You can use press vs poor ballhandling teams, and M2M when your DEF ratings are better than your opponent's LP / PER.
- Element of surprise - can be tougher for opponents to gameplan vs your team.
Cons:
- Recruiting for 2 diff defenses. This is huge at D3 (and D2 to a lesser extent), where every player is flawed in some way. If I play M2M, I can prioritize (as an example) DEF more than STA. If I play press, STA might be more important, and I can sacrifice a little on DEF. But if I'm playing a combo, I have to find guys who have ATH, SPD, STA and DEF. My pool of qualified guys is a lot smaller than if I play just one defense.
- Playing young players. Freshmen and sophs have to learn two defenses before they can contribute.
- Less practice time for core ratings.
So imo, unless you're an A+ coach and can recruit all-around players, I think combo's negatives outweigh its positives at D3 and D2.