Soul Reaver is much improved over Blood Omen, the graphics being the most notable improvement.  The story line is grusome, yet completely involving.  You can do alot of damage to your opponents and Kain is probably the most dynamic and pitiful character (appearance wise) to date.  The dark, moody atmosphere is not only necessary, it is downright cool and adds a great deal to the game overall.  The music score is fairly decent and controls are tight.  Load times have been much improved as well.