Whereas I loved the story. The Phantom Menace is all about Palpatine manipulating everything so that no matter what happens he wins, and leads the galaxy inexorably on a path to crowning him Emperor. It's a great big foreshadowing exercise, which a prequel needs to be.

Of course when you're George Lucas you have to foreshadow with the subtlety of a lump hammer. You have to have a muppet babies version of Greedo and tell him "you're going to come to a sticky end you no good meanie".

The difference in tone for me is that the first trilogy is set entirely in frontier worlds: Tatooine, Hoth, Dagobah, Bespin, Endor. The second trilogy is set mostly in civilised worlds like Naboo and Coruscant. We see shopping malls and public transport and factories: it just feels different. It's not so much the action itself, as where the action takes place.