Blender since version 2.5 (and 2.6) made HUGE improvements and should be considered a professional tool for 3D artists.
Watch these videos (published 3 years ago):
"Completed only using open source tools in a Linux environment. Blender is the only tool mainly used for production. Only other tool used was GIMP for texture creation. Post production and editing also done inside blender.The renderer is blender internal renderer."
full render 3D office:
http://vimeo.com/12198312
http://vimeo.com/12202062
It took them 70 work days for team of 6 people, 40 work stations, 45 render blade units. They rendered 11,500 frames and cut it down to 7,500.
