I like how easy it is for me as an individual user who doesn't have much experience with data conversion tools or software development in general.
It's very simple but effective when you need something done quickly that requires little effort from yourself! There are some things about J2CSO which could be improved such as better documentation of features/functionality etc., however these can easily been found through online research so not really any major issues here aside maybe finding more tutorials written specifically around certain aspects? For example there was no clear tutorial explaining what happens if all columns don't match up between source file & target files - i had to look at their support forums before realising they would only accept one column mismatch per row rather than multiple mismatches within 1 line of code- meaning my script needed tweaking slightly afterall :) However once again great product overall though perhaps minor improvements made available by adding additional guides into docs folder might help future.