Oh, I should also make note of an earlier and very similar build I have here:
Entropic Warrior | NWN2 Character Builder
While the build is a Blackguard, I don't tend to think of it as an Anti-Paladin. IMO an Anti-Paladin isn't going to be Bard-based, but rather some type of High BAB melee class.
The fact is though that the attack numbers are the same when this build has Inspire Courage on.
The real differences are:
1. The Bard-based build has significant magic at its disposal at epic levels (..and considerably better than just about any Paladin I might add).
2. The Bard-based build has a net +6 damage (30 level) most of the time both from an additional +8 Strength and +2 from Inspire Courage.
3. The Fighter-based build can add a LOT more damage via Improved Power attack.
4. The Fighter-based build has better attack numbers for most of it's progression, particularly at lower levels.
5. The Fighter-based build is MUCH better when fighting multiple opponents. (..the Bard-based build has Cleave, the Fighter-based build has all 3 Cleaves.)
7. The Bard-based build has EDM as soon as you can get it. (..The Fighter-based build must wait an additional 5 character levels in comparison.)
8. The Fighter-based build has Divine Shield "front-loaded" at level 12. (..the Bard-based build doesn't have it until level 23.) (..the Bard-based build counters with more Tumble bonus and RDD bonuses.)
9. The Bard-based build has higher saves.
10. The Fighter-based build has better protection added to those saves (..Steadfast Determination and Epic Resilience.)
11. The Bard-based build has additional types of special attacks (..Knockdown and Disarm).
12. The Bard-based build has additional protection from Fire and Paralysis (..though Paralysis is unlikely with a high save).
IMO the *key* differences are that:
The Fighter-based build is better for the first 20 levels. Further, it's considerably better against multiple opponents - for this reason alone it's vastly superior for the campaigns (where there are so many "mobs").
The Bard-based build is probably better against single tough opponents once nearing the end of it's build. (..in large measure due to an extended Mirror Image and Displacement spells ..and the Disarm/Knockdown ability.)
Despite the superior saves of the Bard-based build, AND its additional protection from Fire and Paralysis at high levels, I'd still say that the Fighter-based build is better overall against most magical attacks.
The reason is the seemingly disproportionate number of times I've seen a "1" rolled in a save. Having immunity to an "auto-fail" roll turns out to be a big thing. On the other hand you could drop the Bard-based build's: Improved Critical Scythe, Knockdown, and Disarm - and replace them with: Toughness, Epic Toughness, and Epic Resilience (respectively).