There has been serious performance issue on Win8 build since the early version.

Essentially, when the number of tasks grow beyond 400, the performance issue starts to be noticeable, and quickly it becomes unbearable.

Syncing will hit cpu uage on 100% for quite a while. And after hitting enter in the quick entry dialog, you'll have to wait for several seconds for the task to be inserted.

Some very inefficient code (or the use of some less optimal .NET data containers) may cause this issue.

Hundreds of tasks may not be that likely for an average user in doit.im, but for a program that serves Pro users, this is a very common scenario. Performance optimization for win8 is probably overdue and worth a higher priority.