Can anyone hear the difference when you add REL subwoofers when playing two channel

I wonder if anyone else has had problems hearing a difference when adding REL subwoofers to their two channel systems?  I have gone back to a reputable dealer in town to listen to a pair of Vienna Acoustic Mozart's paired with a REL S3 and I couldn't detect a difference when they added and subtracted the REL.  I wonder if this was because the Vienna Acoustic Mozart's are already can extend down to 30 Hz.  I have also read reviews on the Mozart's and they said one of their criticisms was they felt the Mozart's to be too boomy in the bass.  

The dealer keeps telling me I am expecting to hear a more punchy pounding bass sound and that is not what I should be listening to.  He keeps saying I should be listening for greater depth and space to create a larger sound stage.  He went on to say if I had a subwoofer that delivered too much bass, they would eventually drive me out of the room and spoil my enjoyment of listening to music.  I thought I had sensitive ears to sound, but in this case I wonder if I am tone deaf.  My fear is getting a pair of T/9i's in my home and my wife telling me I wasted our money because she could not hear a difference. 

There must be a reason why so many dealers have told me their first pick would be a REL because they are so musical.

I also question why REL manufactures their subs with such low wattage?  For example, their S3 delivers only 400 watts and their T/9i's deliver just 300 watts.  When comparing them to  subwoofers like JL, which deliver 750 watts to $1500 watts, maybe REL subwoofers are just too wimpy.