I have to disagree. Mostly your right, but I have a very specific fail case that happens every time with Siri. I can't call my wife by name. I have to always call her "wife", because it thinks I want to change my name. Now it's a name in the address book, but it never matches against it.
I can also use it dictate an email or search the web, and occasionally it fails (maybe 10% of the time?), but it almost never gets my wife's name.
Well, I wouldn't be surprised if Google's voice recognition is better than Apple's (which is powered by Nuance, right?). Also, recognition for search queries and voice actions tends to work better than completely unconstrained text transcription. Of course "perfect" is an exaggeration, but my point is that Google's voice query transcription has passed a threshold and it is no longer the least reliable part of the system.
In a somewhat related note, I've noticed people search on some websites fail with Vietnamese names because surnames are interpreted as prepositions, and thus dropped as a stop word.
I can also use it dictate an email or search the web, and occasionally it fails (maybe 10% of the time?), but it almost never gets my wife's name.