We're running into a strange situation where Windows Outlook users are experiencing extremely slow performance in updating their inbox/calendar/anything in Outlook if running in cached mode.
Mobile devices, Mac / EWS clients, sending mail, non-cached mode inbox updates are all OK.
It took nearly 10 minutes to get past the initial configuring profile screen with the Outlook 2010 animation after recreating the profile, manually deleting the original OST. It's now been more than 45 min and the OST is barely 4MB.
We're running in a 2007/2010 coexistence environment and this started happening this morning.