I flipped back and forth from 2-3 to 3-2 in D3 and tried it last season at D2...it worked well for me at D3, but the verdict is still out in my mind for the 3-2 at D2...I think it can still work, but I was at a speed/athleticism disadvantage in pretty much every game with the team I inherited, so it was hard to get an accurate picture of how it would fare with an average/above average stable of D2 players.
When deciding which to run I generally look at the LP-PER ratio of the opposing team (the higher the PER rating compared to the LP, the more likely I will go 3-2), their propensity for 3-point shots and their post players, particularly the players' individual rebounding ratings. For the most part, 3-2 is something I'll do only if I have some solid rebounding PF's and C's and feel I can survive largely on their skills on the glass. If my opponent runs a power forward in the small forward slot, a SF with a PF/C type rebounding rating, or two centers at the PF-C slots, it's going to be extremely rare to see me in anything but a 2-3. Ditto if the opponent is obviously set on minus 3-point settings with his guards. The biggest thing to protect against if you run with a 3-2 is getting eaten alive in the rebounding department. One other thing to keep in mind is that the engine won't halftime adjust you out of a 3-2, so you really only want to run it if you're certain you need the extra perimeter defense...you don't want to pull out a 3-2 and see yourself halftime adjusted into a 3-2 zone (-2).
My mentality behind using the 3-2 is that I'm trying to dictate where I'm willing to lose the game -- I'm selling out so as to not open up a box score and see my opponent going 12-for-23 from 3 pt land or something. If the opponent is already trending to play the game inside, then I want to go 2-3 to utilize the extra rebounder down low and limit second-chance opportunities. Keep in mind the most recent update supposedly gives 3-pt. shooting a downtick across the board and adds emphasis to rebounding. Like you, I'm in Naismith, so I haven't experienced it yet, but the description would seem to describe a change that makes playing 3-2 for a full game less of a need.