Though I had asked this question. And over this period of last 5 months , I gained some information and knowledge on Oracle commerce 11.3 . So I will reply to my post myself. Getting some Deja vu. Maybe I have done this before.
REST Services is the way to go
As Industry has shifted big time towards the web service based implementation, it was a need of the hour to move towards this direction more aggressively than it was being done in Oracle Commerce. A new REST framework has been built which is more simplified and this comes with the JSON responses already having the endpoint URLs so that there is less burden on UI end. Further, the Oracle guided search configs have been updated to be JSON based as compared to traditional XML based to support the REST. And there are guided search specific REST APIs as well.
Push towards cloud
As the world moves towards , Oracle commerce is following as well. After already launching Oracle Commerce cloud, with this version business gets an option and ease towards moving to cloud in future upgrades as this version can run on commerce cloud without much changes. Well, technically.
Oracle Commerce Guided Search
Mdex version – long pending change. No more 6.x its 11.3 , Experience Manager – Puff.. No more flash in workbench. its js based. So so easy to use and find out issues. Type Ahead – It was always a pain to index typeaheads separately. But not anymore . Big relief .
Bye bye flex
There are many other small enhancements you can find in release notes. Or you can share in the answer below.