The Usher's use much high resolution drivers than what Proac uses. With higher resolution comes setup issues, so your dealer may or may not have optimized how the speakers were setup.
If the speakers you heard had any other speakers in the room, that can lead to lumpy bass, also if the speakers were too close to the read wall, or if the room has problems with standing waves this could all lead up to lumpy or boomy bass.
As per treble, good clean treble requires the right components, cables, power conditioning, and source components.
If the speakers are very revealing that you will hear both the good and bad aspects of the recordings you are playing.
Many dealers are not the best in setting up their own demo rooms, this can be due to the huge costs required to find just the right group of components that will make a particular set of speakers come alive.
Trust your ears if you were impressed buy the Ushers they are really fantastic speakers.