Sound wise, it's not lacking. On par with my Bang & Olufsen equipment, better than my Harman/Kardon equipment (my HK Sabre SB35 wireless soundbar does a better job at simulating surround sound, but the sound dynamics of the HP are clearer).
Like mentioned by reviewers, Siri is lacking. For example, though Siri can read my messages, it can't answer a question like "what's my name?" (but the iPhone Siri can). Which I understand could be due to the inability to differentiate between / identify people speaking. But if Siri is able to read messages from my device, it should at least be able to tell me what's the name of the person whose Apple ID it's assigned to.
I'm not disappointed though. I purchased it while already looking forward to this year's WWDC.