If you had purchased the The Only Exception from the Anniversary Party, it has a truly amazing MDB, 14 for the level 20 version, 20 for the level 25, and so on. So if you were building a high-Dex version of a caster Druid, that would work wonders. But I'm not aware of anyone doing that. The reason is, you're much better off spending all of your stat points in WIS and CON, and then leaving the rest alone. The PRR and MRR from Heavy Armor and Shield easily makes up for whatever reflex you might scrounge together, and given reflex is the worst save for Druids, well, you're unlikely to make it useful.
What about picking up a couple levels of Rogue for trapping? The capstone for Season's Herald is uninspired, so I could see that. But again, you run into the poor reflex save problem and you then have to wear light armor, not medium.
So QuantumFX is exactly right, losing PRR, MRR and AC is a significant loss. I don't know what magaiti would like to spend the points on instead of NP, but don't overlook what else you get for that expenditure. The Nature's Defense stance with core 3 costs 11 APs, and gives you up to 40 hp, 29 MRR, 20 PRR, and +3 saves, not to mention any other enhancements, nor to mention the extra AC and heavy armor + shield-based PRR. It's a LOT to give up. Trust me, as you rise in levels with your defenses, healing, Rage, and spells, this build is a beast.