Pros:
- you can use native data structures instead of continually wrap / unwrap
- you can use native methods on them (map, filter, ...)
- hence (almost) no interoperability problems with other libraries
- overall your coding style doesn't change so much
- (possible perf gains since the js engine knows the object is frozen? - I really don't know)
- EDIT: 0KB dependency
Cons:
- you must find / write a way to update efficiently