I sent off an e-mail to Outlaw inquiring as to what type of slope to expect on their upcoming pre/pros. They said that they were considering either 2nd or 3rd order (12 or 18dB/octave) slopes. They said they wouldn't use a 24dB/octave slope in order to avoid group delay. It seems to me that too shallow a slope has inherent disadvantages. Your mains might be sent reproduce bass information beyond their capability, while the sub would become more localized by reproducing higher frequency bass. What exactly is given up by using a more rapid rolloff at the crossover point? Do you lose the "blending" between the mains and subwoofer with a steep XO? How does group delay factor in here?