I like that it helps me to easily get data from different sources (RDBMS, NoSQL, etc) and analyze them with my own code. The documentation is not very clear for beginners, and sometimes you need to try several times before getting it working well. There are many functions in graphext which are not documented, so it's hard to know what they do exactly. Also, it would be nice if there was an option to show graphs in real time while analyzing data. It provides great tools to help with data analysis and visualization of your data.