Von Zorn for the win!
For example, the 9th age fantasy battle rules are arguable more balanced than any edition of Warhammer Fantasy, but they're also bland in comparison. However, it's the gaming-oriented and winning-oriented player base that makes the game non-enjoyable for me. Playing with friends in the living room goes fine, but then again we can play other rules with more nuance and ridiculous oldschool fun.
Over here, AoS is usually played in the more casual manner, the players are interested in collecting and painting figures. Also, still!, the critics of the game seem to be those who don't play it very often. I guess in the sphere of balance, AoS is one of the better games around, although it's hard to keep the balance when new units are created all the time (GW sells figures, after all). Still, the head game designer plays the game himself competitively in tournaments, which always is a good thing regarding balance.
So probably the shopkeeper was right, in a way. But then again in the bigger scene and comparison his opinion is not totally justified, and it doesn't really matter that much.
-Z