If you have plans to do another upgrade that is going to cost $600-700 plus box, I would skip this $500+ upgrade for a slight if any noticeable increase. Spend some on sound deadening and have you a big ass nice logo inside your trunk. No need to advertise your car for potential theft.
I would be interested to know how the concert series ends up performing. I have a Soundstream BX-20Z and it does a hell of a job on classic rock, country, and some R&B. Most not all modern rap top 40 music. it actually takes away bass from it. I almost think that the subsonic filter needs to be lower but that is only part of the problem. I did read that the audio control epicenter (concert series) was the best for all around performance including rap.