I actually like that the Jedi Council was on Coruscant; it showed just how far the corruption in government had spread that the Jedi (who, one would guess, were surely at one time independent of matters of state) were actually, in effect, a branch of the government.

Now, the overall portrayal of the individual Jedi could have been better - they certainly didn't appear to be the wise, compassionate beings we were led to believe they would have been; none of the new Jedi, Qui-Gon aside, were especially sympathetic characters - but the circumstance of the Jedi being an integral part of the Republic infrastructure works well in the story Lucas was telling. I admit I would have done it differently, but the "corrupt Jedi order" was actually well executed.

I wanted to care that Jedi were being slaughtered, but Order 66 didn't move me much at all.