I have to say I was very impressed with the voices on many of the characters. Graham and Alexanders' voices sound nearly identical to the originals, so you either chose very good voice actors or you managed to hire the same ones.
However for some of the other characters you may consider playing with EQing or other technologies to get the right voice. For instance, Saladin didn't sound nearly as "canine" as he did in King's Quest VI and his voice could use a makeover. Now that said, I don't believe even the original game used any voice modification. Remember the minotaur? He sounded like a regular human being growling as low as he could. I'm sure you guys could top that.