Descriptive Problem Summary:

One wouldn't expect big icons to kill performance quite like they do. This is just a test to show that there's some kind of deficiency somewhere in the render/view building pipeline, and unfortunately, none of the client profiling data shows the source of this render chug:

Demo included:

http://files.byondhome.com/Ter13/Bigtest_src.zip

This demo spams 500 1024x1024 icons with matching bounds onto the map in a fixed location. Move around to see the chug in action. Notice how it gets progressively worse the closer you are to the center of the icons. Also notice how it takes upwards of 50 seconds for them to disappear even though they are destroyed just 10 seconds after creation.

This has zero effect on clients outside of the view.