I think JPA is nice and convenient ( not to mention standardising, as we used to have every individual programmer doing his/her own thing with a jdbc connection).
I
.Net Persistence Api is the equivalent in .Net. Both JPA and its .Net counterpart are set of specifications which ORM vendors or open source community can implement. Hibernate is one of those implementation like we have Entity Framework in .Net. When you switch between two ORM frameworks that adhere to JPA, you wouldn't expect any changes in code to accommodate this change as both follow the same underlying specification.