This game has its own unique style and is, in some places, technically superior to MW4. For instance, MW3 features landscape mesh transform when you hit the terrain with a weapon. This means that you don't just leave a char mark, the terrain actually changes when you strike. MW4 leaves a decal and that's it. The decal then fades or dissappears suddenly after a period of time. In Mechwarrior 3, if you leave a crater, it's there until you leave the map.
Mechwarrior 3 was the bundled software that came with the second production run of the Microsoft Sidewinder Force Feedback Pro 1.0 joystick. The first release was bundled with Urban Assault.
It was an excellent choice. Realism takes on a whole new dimension when your aim gets thrown by the vibrations of your Mech landing its step or you have to compensate for machine gun drift because the stick is feeding you the recoil. Just make sure everyone in a multiplayer game is using a FF stick. You'll be at a tremendous disadvantage otherwise!
The German version of the game has been censored: Foot soldiers disappear as soon as one aims at them or one is in an position to smash them with the mechs' legs. There's currently no known way to change this "feature".
If you're new to BattleTech and having trouble in the single player missions, one tactic is to shoot at the legs of your enemies. But don't do this when playing against humans... they tend to get REALLY mad about that. ;)