I have owned them both along w 5a and the 7’s. ( still own the Treo CT and the 7’s - you can see both setups as well as others in the vintage room. The Treo CT has a better tweeter, midrange and super importantly cabinet than the “ sock “ series which offer stunning value for $$. They are much more pistonic with greatly reduced cabinet coloration and should be carefully level matched - easy to sell the louder speaker. The 5a has the killer push pull sub and if setup correctly is a wayyyyyyy better speaker than the 3a ( as it should be ) however a 5a pulled to far out into a room will lack the slam of a 3a within 2-2.5’ of the rear wall due to the acoustic coupler. You have one of the absolute best speakers on planet, enjoy the music. Stop by for a listen IF u get to Seattle or Carlsbad sometime.
best to you
jim
best to you
jim