I like the D&D Wiki variant quite a bit. The main changes are invocations known (you get more, in that shape and essence invocations are tracked separately - very good idea), iterative attacks with the eldritch blast (it helps to keep EB relevant at mid to high levels), and eldritch surge (which isn't explained too well, and I don't really like the way they handled it). The wonky EB damage progression is also fixed. Very much appreciated are the 4+Int skill points/level - now you can actually make use of the Warlock's good list of class skills!
Balance-wise, I think most of these changes just help to make Warlocks a little more flexible, and to keep them at all interesting in a mid to high level game. The Complete Arcane Warlock loses much of its luster from level 6-8 onwards. Also, the very limited number of invocations known made it a pain to pick blast shapes and essences - especially since you know that your blast damage won't be able to keep up at all once the group's Barbarian hits his stride.