IMHO.
MTW Totaly OWNS RTW.
You should get MTW and VI if you like STW and RTW.
MTW has So much more replay value that its Always Worth buying,
As far as Im concerned.
MTW will still be worth buying in 10 years time.
Even if the whole Multiplayer scene for MTW dissapeared.
MTW would still be worth buying Just for the single player Game.

Any way im gonna shut up now b4 i start bashing RTW :)