Vandersteen is a much smoother performer, the Paradigm has it fans and is a great speaker but is no doubt an easier speaker to have problems with fatigue. With the 3A and the Vandy sub combo you have pretty much a Quatro wich is a speaker you could easily live with for the long haul.
I have Vandy 2Ces and used to own Paradigm 100s 1st version. The Vandersteen is a better speaker in many ways including the fact that it is time and phase correct. Plus it will extend lower with good amplification.