Is Haer'Dalis a better blade than the player can make?

Chronicler

Because of his innate tiefling bonuses.

Christian79

He also gets to specialise in Short swords and Long swords.

OrlonKronsteen

His ability to specialize is nice, but it isn't the equivalent of a fighter specializing. Unless it was changed in 2.6, he will not get the extra half attack per round that fighters get. A PC can have better stats - obscenely so if you've used tomes from BG1. So a PC with 19 strength is going to be better offensively than Haer'Dalis will, even with his ++ bonus. A PC with a decent constitution (and better HP rolls) will obviously be hardier, too. The advantage of a possible 19 dexterity goes without saying.

The tiefling bonuses are mostly situational (fire, cold, electricity) and a PC can achieve these by other obvious means. 15% physical damage resistance is nice - and not situational - but in actual performance it doesn't mean much. He is still very squishy if not protected by spells or using defensive spin. If played correctly, a blade should not be getting hit, so the %15 bonus shouldn't factor in unless everything goes absolutely south.

So, I guess the answer to the question depends on a PC bard's stats and hit point rolls. Given equal or lesser ability scores, H'D will be more powerful. But if you min/max, a PC can come out stronger. However, as is the case with just about every class in BG2, gear can change the balance of things. Give H'D a strength belt and the girdle of fortitude and things start to even up.

Christian79

It also depends on role, party composition and if you play with SCS. His natural resistances cannot be dispelled and they help reaching undispellable total immunity to certain damage types using gear, which allows some tactics which might be more dangerous for player blades who must rely (more) on temporary buffs. And he got his rather unique swords. Depending on how you use his natural features you might not end up necessarily more powerful, but the playing experience could differ somewhat (also since he is quite squishy).

jmerry

It wasn't changed in 2.6; his specialization works exactly as it did before.

One other thing about his race: "tiefling" is treated internally as a variant of "elf". So he gets the strong charm/sleep resistance and an additional +1 to hit with certain weapons. With his specialization, Haer'Dalis gets +2 to hit and damage with short swords and long swords.

Also, when you're comparing recruitable NPCs to the PCs you build, remember that there are a number of protagonist-only perks. A familiar, Bhaalspawn abilities early on, the hell trials later...