I've pushed my 7D to 6400 during night sporting events and got great results.
FYI--went to Bosque in January for a week-end and wasn't happy with the photos. They had excessive noise and were not very clear. As I'm in VA this week and right next to the Canon Repair Center, I took my 7D in and they had to make electronic adjustments to the focus screen which was causing the excessive noise. Noise was unacceptable even an 400 ISO.
Natures Photo wrote:
Not boring at all, nice shots. I see the noise at ISO 800. I shot at 2000 recently and the results with the 7D were very disappointing.