I found Siri performs quite well for me. Not perfect by any means, but I use it regularly and rarely have issues. A lot of my use is in the car with the A/C on so that's a fairly noisy environment. I use it with the built-in mic, not a BT or wired one.
The main difference I see is that the article seemed to focus on searching. While I occasionally use Siri to search, I mostly use it for things like:
- Read an incoming text message to me while I'm driving and reply to it.
- Take a note (in the car or anywhere else). I even add-on to the note using voice.
- Check my calendar.
- Set up appointments in my calendar.
- Initiate calls
- Set up reminders (I'm especially fond of location-based reminders)
As others posted, accent and diction probably make a significant difference so YMMV.
I wish there was a setting for Siri to ignore Bluetooth connectivity. I still want phone calls and music to work with my car's BT, but I'd like to be able to hold the phone up and talk directly to Siri because the internal mic is so much better than the one in my car's BT. I pretty much don't use Siri at all in the car because it sucks so bad with the BT, but I want to use the phone/music function.