I never heard the Puppy 7 but heard the previous model... The sound was VERY dynamic (very in your face sound) but I couldn't listen to them for more than 30 minutes at a time... In my opinion, the puppies are very fatiguing. On the other hand, the Utopias were more delicate. They sounded more laid back (compared to the Wilsons). I auditionned both speaker sets with the same equipment (Classe Omega amplification with Wadia 861X CDP).
I guess it comes down to which coloration you prefer.
If I had a choice, I would go for the Utopias.
Note: I don't own any of this equipment...