Got my Z10 yesterday, here are my findings in terms of shortcomings.
1) Delete from Handheld / Delete from Mailbox & Handheld toggle is gone, courtesy of ActiveSync
2) Deleting a message in an activesync account in MS Outlook, does not replicate to the BB10 Hub. The message you delete in Outlook is still shown in the BB10 hub, and the flashing red light won't go away until you also delete it or read it in the hub.
3) You can't hide the address bar in the browser.
4) You can only sync (auto upload to cloud) photos and media with Box, not DropBox.
5) No way to continous scroll the window panes. You go all the way to the right or left, and you stop at the Hub, or at the end of your icons.
6) Camera locks up pretty often. I've had to do a battery pull twice to recover, camera app stops responding to all buttons or touch input.
7) PIN to PIN messaging is gone.
8) Deleting an email needs to be accessed by long pressing the email, then clicking the trashbin icon on the sidebar. IMO, the delete icon should be visible at all times on the bottom bar, maybe beside compose.
9) Rotation changes are very slow.
10) No way to color code emails from different accounts for quick differentiation.
Other than these 10 items, I am happy with the device.