Yes, I have used that guide in the past and it has definitely helped to reduce memory usage and increase performance in my grid based applications.  I think I employed every possible suggestion in my simple demo from that guide.

It looks like my demo is close to maxing out the performance of the grid, yet I am not even close to performing updates as required by a realtime financial ticking application.

Every 200 milliseconds, I update all of the properties for 250 random objects and fire a single INotifyPropertyChanged event for each object when it is updated.  In addition I have summaries for each decimal property.  You could certainly imagine a case where I would have 1000+ rows in the grid with 100+ properties each firing INotifyPropertyChanged events when they are changed most likely at a rate faster than every 200 milliseconds.  I'm just curious if there is a suggested method of performing realtime update functionality with the grid or if I've simply pushed it to the boundaries.