Klipsch Heresy IV

Heard the Heresy IV at my local dealer. It was hooked up to a Luxman SQ-N150 a 10wpc tube integrated. Gives you better bass than the III. The speaker is rear ported. This gives you a fuller sound. A nice improvement.

I just got them. Powering them with 8W 300B. Heaven 

I can't quite adjust the fact the Heresy's are no longer seal boxes. While the bass may be more plentiful, is it as tight and does it add boominess to the bass? I wonder if there is any loss to overall quickness and clarity?