His bike was a great design. While I do like Grievous and his design, I would hardly say his hand-to-hand with anyone in the film was excellent. He was trying to escape in pretty much every scene he shared with a hero. He failed against the Jedi and ran away in the first act, he failed against ObiWan and ran away in the second act, had a cool bike scene, then died horribly, meanwhile while Obi-Wan essentially only had his hair out of place. A villain that always runs away and fails against the heroes at every turn is a failure as a villain. Obi-Wan is never at any point intimidated, concerned or even unsure that facing Grievous will be anything other than a total victory. As a viewer you never once feel Obi-Wan was in danger so Grievous sort of becomes a bore as a villain. He even stops speaking once the clone army arrives, he just growls and coughs a bit from the time the army arrives to his death. As a viewer you're not engaged and are just watching things happen. Imagine if Vader never spoke to Luke once they started their duel in ESB, or if the Emperor never spoke during the climax of ROTJ. Meanwhile, in the old Micro-Series, Grievous taunted and hounded the Jedi, he was competent, scary and they were absolutely terrified of him. I still find that Grievous to be very memorable.
Sorry for the rant, these are really larger storytelling issues more than just General Grievous issues, but it is the reason you don't really care about Grievous as a villain, despite him doing some cool things.
The Prequels had so many great designs, it had so much going for it, it's just such a shame how they turned out.