Them being clowns and Grievous being turned into more of a bitch and Dooku becoming Snidely Whiplash was mostly Clone Wars retcons.
Then you also had the Clones' DINDU NUFFIN cycle added on top, which kind of dulls their edge when they're all suddenly good, instead of being professionals hiding a darker side to them.
For fuck's sake, they were cloned from an anti-hero bounty-hunter who had no problems going full IRA/Wahhabist against innocent senators who wanted to stop a war from breaking out. Dooku picked the guy because he murdered the shit out of Jedi on some battlefield, then killed a Dark Jedi druglord. Then all of a sudden, the clones all come out tidy and straight like boy scouts? My ass.
I wanted to see the Null-ARCs, Clone Commandos, and even Clone Assassins do black-ops shit like killing Jedi who questioned Republic orders then pinning their deaths on the Seps, or killing local leaders before they can make the choice to secede and "arranging" for them to get replaced by Palpatine toadies. I wanted to see the dark side of the Republic where the clones massacre half of a planet's populace because the people voted for the Seppies. I wanted to see the Clone Army to warcrime their way and slowly evolve into what would become the fucking Stormtrooper Corps. But no, instead, they separate the two, and act like the clones never got into it, even though in the real lore, the clones were the monsters of the Stormtrooper Corps, where they bullied the shit out of the birth-born recruits and they were the ones skilled enough to kill the Order 66 Jedi survivors.
Someone like Cal Kestis would get wiped out by the 501st Legion during their missions. I can imagine him as the Jedi who started the Death Star riot, and I can easily buy the 501st clones killing him during said riot.
The only dark side to the Republic we see is when the clones and Tarkin persecute Filoni's waifu Ahsoka, which, given that she resisted arrest and even punched members of the military police in the face, would justifiably give Tarkin enough ammo to get her relieved of command and tossed in a jail cell for a few months, even though she was innocent of the Temple bombings.