There are so many cons to the 4.7 OS. The only pros is that it's touch friendly, but the tour isn't so it's not even a pro, and the UI is a little more pleasing to the eye.
As for the cons:
4.7 is huge, and takes a LONG time to boot. The Tour is much faster than the Curve, but takes twice as long to boot.
3 Speed dials cannot be changed, not even the W (or 1) that is voicemail by default. It could be changed on 4.5
See:
http://supportforums.blackberry.com/...&thread.id=558
Contact Alerts half as useful as Exceptions and are still buggy.
You can't disable and enable Contact Alerts like you could with exceptions. A lot of deleting and re-adding, and they STILL have the same bug from 4.5.
See:
http://supportforums.blackberry.com/...&thread.id=472
For people that live on the edge of their network coverage area (like me at home), they get no bars where there Curve used to get at least 2. All day long I hear people complain about not being able to hear me now. Most likely software related.
See:
http://supportforums.blackberry.com/...&thread.id=267
A handful of GPS apps do not work. (Most likely not the fault of the OS, but the software as I have read that the 4.7 OS uses a different method of retrieving your location from an app.) One popular app being Google Maps.
See:
http://www.google.com/support/forum/...bb8c247f&hl=en and
http://www.google.com/support/forum/...0195f6cf&hl=en