Yeah, hands down. The Druid summons hit harder and live longer, plus druids can swap out spells to summon. The Summon monster spells instead summon overall weaker creatures, but with more varied options. Most of those options are negligible compared to the mountain of meat the just improved grab'ed the BBEG.
The monk unarmed strike is separate from natural weapons. Being big bumps damage a little, but monk won't bump up claw and bite weapon damage dice. Nor does flurry work with natural attacks since "When using flurry of blows, a monk may attack only with unarmed strikes or with special monk weapons (kama, nunchaku, quarterstaff, sai, shuriken, and siangham)."
It's mostly in reflex saves, land speed, AC, and the other passive defenses the Monk gets. Ninja//Druid is a killer, though. Wildshape into something with a lot of attacks and pounce... then use the Ninja Ki Ghost Strike (or was it Ghost Step) to go invisible as a Swift action and Pounce someone for many attacks, each of which gets +Xd6 Sudden Strike damage on top of it.
Not really needed - NE Druids are quite viable, and most Druid PrC's don't add alignment restrictions. There's the Blighter from Complete Divine, but it's... not worthwhile, and seems to be more intended as a flavorful adversary for a nature-friendly party than it is a PC PrC.
