We have applied SP13 to our development environment, and till date have'nt seen any specific issue after SP 13 and system is pretty stable.
I will update you in case we face any issues due to SP13.
Updating this thread with information of some issue we faced after migrating to SP13.
1) Trigger written on Vector field with event FieldChangedByUser doesnt fire.
2) There are some issue with the editability constraints with ARFTableButton.
3) Deletion of custom tab rearranges the contents on the previously visited tab unless you log out and log in again.
4) Split account type change doesnt trigger properly.
I would keep on updating this list as and when I find more issues. As of now there are no fixes available for any of these issue.
Thanks and Regards,
We too have seen #2 you point out. We resolved this by making the editability always true in the classproperties for that specific object. It then seems that it will look to any editability conditions you may have set beyond that. Dont know why, but this works. It is as though Ariba defaults the editability to no for this. ................Just an FYI.
Thanks for sharing the other issues you have found.