Yes, there are lots of goodies in the Defender tree (I'm spending around 40 points), but you also need some DPS. A good Paladin tank needs both offense and defense. Not only do you want to be able to tank when the situation warrants it, but you also want to be able to contribute as much DPS as possible. Likewise, there are traps built into the Knight tree, so you have to pick and choose carefully, to create a build that works well.
In the meantime, I don't think the developers are going to change the basic premise / design of the trees. I've also posted detailed suggestions on how to design a tree that is optimal for a Knight, and a tree that is optimal for a Defender, but I think that got completely ignored. Instead, if we want to enact change we need to rally around asking the developers for specific fixes to the tree, along with pointing out why it needs to be changed. I'll start...
Please fix the bug that makes you temporarily lose hit points from Greater Stance when you change a weapon!
This is by far the #1 biggest issue with Paladin enhancements atm. I probably do more damage and spend more mana healing myself from this bug, than I take from monsters or traps in quests.