Importing a 1000 event iCal calendar into Chandler I get the following approximate times.

Attribute Timed	Linux QA Machine Build: debug_20050610124237	Mac QA Machine Build: debug_20050610100042	Windows QA Machine Build: debug_20050610133918
Importing calendar	12 seconds	35 seconds	14 seconds
Switching from All view to Calendar view	3 seconds	6 seconds	3 seconds
Switching from Calendar view to All view	2 seconds	4 seconds	2 seconds
Creating a new event	1 second	2 seconds	1 second
Stamping event as email	1 second	3 seconds	1 second
Moving event in Calendar view	instantaneous	1 second	instantaneous

I also loaded the calendar into iCal:

iCal on Mac QA Machine
Import time+Calendar rendering: 3 seconds