Is it possible to be a national contender consistently while playing a zone? Speaking mainly for the D-2 level

yes.  although i'm struggling a little early this season, I won a title in DII playing zone at UAF 3 seasons ago.

I'll get back to you in a couple of season to make sure it is consistent, but yea, you can be successful.       Haasdr taught me a lot this last year     

I don't honestly think there are really many advantages to playing a zone. You might see a tiny bit fewer fatigue issues, but in reality the attributes that make a zone defense successful will make a M2M defense successful, or even a press defense(plus more stamina). People like to say you can 'hide' a bad defender in the zone, but it still will hurt your team defense to play guys with poor defensive ratings.

Zone will also hurt your rebounding and make you vulnerable to 3 point shooting.

While man is clearly the best when it comes to rebounding, I would say zone is an upgrade over press in terms of rebounding. That being said, man is probably the most effective at this point with press in second. 

I run zone-press with success. One thing I'm seeing since the 2/3 update is the 3-2 seems to be more effective than the 2-3. Anyone else seeing this?

Note I'm D2 and regularly run a 3 guard offense... or a 2 guard offense w/ a SF with high PE and SPD... with a PF and C with high REB and ATH

Most of my players have poor defensive ratings and I have always tried to hide this with the zone but I am consistently getting knocked out in the 1st and 2nd round or this year I didn't even make it to the real thing but won the PIT. I just want  to take that next step and am curious as to whether or not my defensive style needs to change to do this

You can do it. Most say DEF doesn't matter, but you need some points there, just not 70-99 type ratings. REB, ATH, and BLK is imperative from your 4 and 5 spots and zone works really well. Especially if you can compliment those shot-blocking bangers with speedy guards on the perimeter. The X factor is a SF with SPD, ATH, and REB and those are hard to find.

ok thanks bullet

you need def ratings no matter what. a zone with bad def ratings is still a bad idea.