you are right, not everything works. There still lacks some menu items for me, eg.: View > Full Screen or File > Print Preview, but otherwise it looks pretty good. There remain only a few menu errors.
The pop-up at the bottom right of frame when downloads completed appears here on 98SE and ME.
I've done some more tests, and I'm afraid the notification at the bottom right of frame for when downloads end is definitely not working for me with that configuration.
I assume this applies to all these notifications, e.g. for blocked pop-ups.
If I set the KernelEx mode back to Windows 2000 it starts working again.
I certainly can't use Opera without access to the settings menus!
I tried the comp. mode on five machines and on one the mode doesn't stick. But I haven't found the reason yet. Does it sticks for you?