The Jedi Starfighters

I understand that GL wanted to foreshadow the shape of the OT Stardestroyers. The Episode II Jedi Starfighter was okay. But in Episode III they also implemented the Tie Fighter-like cockpit & extendible wings which made no sense at all. It's the unscheduled child of a Stardestroyer and a Tie-Figher - 1. It looks forced & dumb. 2. The extended wings block the pilots view to the left & right side.

Placement of R2 Units within Prequel Starfighters

Another design flaw. GL wanted to have Astro-Droids in the Prequels but his choosen starship designs made a meaningful placement of R2 units absolutely impossible. Take a look at the Naboo Starfighter when R2 is in there. It looks like R2's legs were detached from his body to fit inside the designated port. And let's not forget the "awesome" R2 Unit Eject Function of the Episode III Starfighters.