I hope you meant ■■■■■ as in wussy. We don't censor people for language here, because we trust you to be mature enough to do the right thing.
Haer'Dalis is pretty useless in BG2 - he can't tank, he can't reach the top echelon of spellcasting, his lore skills are diminished because he's a blade and his bard song does not improve with levels, so he essentially ends up being mediocre at everything. In other words, there are better NPCs out there if you want to specialize in something.
BUT if you take him into ToB, he has the potential to add a lot more value to your group because of three abilities available to him:
- Enhanced Bard Song (which makes his song like that of a skald and adds +4 to AC, THACO and saves for the entire group and makes them immune to Stun, Charm and Confusion);
- Use Any Item which allows him to use any item, including 2H swords, wands etc;
- Assassination, which means that each attack he makes is treated like a backstab, with at least a x5 damage modifier.
These three abilities increase his value by at least 200% IMO. But only if you're willing to put up with him till then.