Very true. I'm aware not all clones followed the order. However, the vast majority (probably more than 99%) obeyed Order 66 and purged the Jedi without remorse. Now, this doesn't resonate with me as I can't see the clones being as emotionally tied and invested as they are in the CW cartoon. This is all subjective opinion, and is not fact.
I hope Rex turns out to be a defector as he learnt a lot from that clone who left the army and had a Twilek hybrid family on a farm. Anyway, yeah I agree it's good seeing Anakin in a different light... but surely he couldn't have changed from a whiny brat, into a good master, and then back into a whiny brat for the start of ROTS, as there's only a 3 year gap in which his personality change can occur lol.
They had semi-remorse. They were good guys, but they were trained in a way to follow that order. They almost had no choice (some refused and saved Jedi) because they were raised that way.
Order 66 pretty much told them "The Jedi, your friends, have betrayed you and everyone you love. Kill them." And since they didn't know about Palpatine being the Emperor they trusted that it was true.