Everyone has their own opinion and no one is really wrong.
I personally prefer IntelliJ, but I obviously see you are asking about the two free IDEs.
Guess what, IntelliJ just went open source and has a free version too that has everything for Spring. The main thing missing is being able to run
TOmcat or server stuff in IntelliJ, and some other features, but for development of code it is all in the free community version. Anyone can use it.
Mark