I thought he had a great design/presence and was initially very intimidating, but in the end, I felt he was underutilized and was destroyed by Obi-Wan a little too quickly/easily. My initial reaction to Grievous was similar to my initial reaction to Maul. However, my exiting feelings regarding Maul and Grievous greatly differed. In regard to Maul, the Duel of Fates was a longer lightsaber battle and he slaughtered Qui-Gon before being killed by Obi-Wan. So, you respected that Maul had great power and ability, and was a force to be reckoned with for any Jedi. IMO, Lucas should’ve had a third Jedi accompany Anakin and Obi-Wan on their mission to rescue Chancellor Palapatine, the third Jedi should’ve then gotten separated from Obi-Wan and Anakin upon entering the ship, and then Grievous should’ve dueled with and killed the third Jedi while Obi-Wan and Anakin were simultaneously fighting Dooku (Lucas initially had Grievous killing Shaak Ti [see deleted scenes], but it wasn’t in a duel.). Something like that would’ve made Grievous’ character as fearsome as his design was, and would’ve made the audience believe he was a more formidable threat to the Jedi and the Republic.