Angels & Demons is technically better than The Da Vinci Code in many regards especially in terms of pacing and a tighter story and while Tom Hanks delivers in his performance and Ewan McGregor and Stellan Skarsgard make for fine supporting roles.
This 4K mastered release of Angels & Demons is certainly an upgrade over its Blu-ray counterpart, HOWEVER, it’s not a huge one nor something worth the $15 price point for a release that didn’t bother porting over the features (even if they were placed on a second disc). Still, if you have the proper equipment you’ll see a good difference.