It's very easy to use, it has great plugins like gulp-livereload which makes debugging easier than before! I have no complaints about this product at all; everything works as expected for me in every scenario that i've used so far (even though there are some bugs being reported).
The documentation could be improved but overall my experience with GULPJS was excellent from start till now - even if we're using several tools simultaneously sometimes you just need something simple yet powerful :) Live reloading of your browser when developing node apps or any other software can help us improve our code quality without having an internet connection everywhere while working ;).