If there are problematic room modes the issue will not be group delay (linear distortion), but the frequency anomalies created. The latter of which would be perceived far more detrimental to 'accuracy' or listener preference even if the group delay was grossly audible (unlikely). Now, if these anomalies are fixed via placement, equalization or another method the group delay problems will be solved as well. Also, bear in mind that it is highly unlikely that room modes will accentuate group delay issues such that they become audible.
This clearly boils down to frequency response issues, not ones of group delay. Furthermore,the perception of 'musicality' is directly related to frequency response (not group delay). The extended bass response and steep roll off often found in ported subwoofers is the cause of the often complained boomy sound (which can be mitigated with equalization). These attributes happen to correlate to group delay because of the physics of how group delay is calculated not because group delay actually relates to percieved speed!!!
If anyone still doubts this statement I strongly suggest rereading this discussion on group delay as it has been addressed multiple times. As such this will be the last time I repeat myself. There is no point in further repetition as it is clear those who have made up their mind based on whatever flawed data presented will not have their mind changed by credibly presented facts.