In my experience ported subs are efficient but the sound is not as accurate as with a sealed box sub. You also want hear the bass through the air than by shaking the floor.
I really like my Dynaudio 18s which is sealed with dual opposed drivers 9in drivers - sounds very musical and reaches below 30hz. The opposed drivers have the benefit that zero ( I mean zero) vibration is transmitted via the floor. I think this is an excellent choice for small/medium room.
I find the the best test for smooth response integration is to listen to a male spoken voice (e..g play a podcast) there should be no boominess when the voice drops through the crossover range, or shift in perceived location. At the same time time the reponse for, say, jazz bass, should be rich, uncolored and satisfying