We have used thyemeleaf in our product to handle dynamic content like search results, user profile details etc..
This was one of first applications that we had built using Spring Boot or any other similar framework but it can be developed without them too if you are good with java language itself!! And also I think its best part would definitely my templates where i could easily write html tags which were not possible before. Not yet found anything as such except some minor issues here n there! But nothing major so far! Its fast loading pages while rendering complex data structures from database tables/objects!!