Try to use phpMyAdmin on a screen with 1024x768 resolution or below.
Create a new table in a database.
You'll find yourself trapped in an insane numver of nested vertical and horizontal scrollbars, and some parts of the overlay window with the column names and parameters are completely unaccessible even by scrolling (mainly because the overlay stays behind the left panel).
This is a regression somewhere between 2.9 and 3.4.5. Version 2.9 was perfectly usable. Maybe it didn't look so "cool" but you could use it.
I am a teacher and use phpMyAdmin in a classroom with the computer connected to a projector which has a resolution of 1024x768. With the new version it is completely impossible to do a class.