Stereophile has a full review with test results of the Q900 here.
At this price range, however, for a column to compete with a stand-mounted speaker, I recommend you also consider the Monitor Audio Silver RX6 ($1250/pair) and RX8 ($1750/pair). They are about as free of panel resonances as mini-monitors and have proprietary ceramic/magnesium drivers that are quick and open. Also quite linear with taut, musical bass.
At this price range, however, for a column to compete with a stand-mounted speaker, I recommend you also consider the Monitor Audio Silver RX6 ($1250/pair) and RX8 ($1750/pair). They are about as free of panel resonances as mini-monitors and have proprietary ceramic/magnesium drivers that are quick and open. Also quite linear with taut, musical bass.