Vader vs Grievous

I just read somewhere that George Lucas created Grievous as foreshadowing Anakin's transition to Darth Vader. That said, who do you think is better?

Cybernetic enhancements:
Grievous has improvements (i.e. Four arms, strength and agility), while Vader's suit was often a hindrance (although it did save his life).

Fighting:
Hmm. I'm gonna say Vader wins here, since he has use of the Force (Grievous only uses lightsabers). Both are good fighters, so it's almost a tie.

Appearance:
While both are interesting, Grievous looks like an ugly insect. Actually, they both look like bugs, lol. Still, I personally like Vader's appearance better.

All in all, I prefer Vader. Your thoughts?