Vice says that sources claim that Apple's pizza is very good:

“I’m a pizza lover, I literally eat pizza on every city I visit, I can say it was a good pizza, the sauce was great. The cheese was melted perfectly and I don’t know which blends they used but it was rich and delicious,” Rodriguez said. “I’m a huge Apple fan and eating pizza at Apple’s HQ was a dream come true for me.”

The last time I had pizza at Apple was back in 2003. I'll have to worm my way in next time I'm in town to get an update on the latest pies.