IMO, for what you have to go through to get the Equalizer's parts (in the underdark), it's just not worth it...not to mention that it's not upgradable in ToB. You're much better off with Carsomyr if you're a Paladin (or, if you have ToB installed, a thief-class as well

).
I eventually ended up giving the Equalizer to Nalia, since she could backstab with it (longsword) and had a better THAC0 than Imoen did. My main character held on to Celestial Fury instead, and alternated that with the Wave.
Cheers,
-Sazerac