Weka is very convenient to use. It can be considered as a good starting point when you're learning to go hand-on on the data processing, model evaluation, training and other topics.

Easy to analyze data, good to do predictions on data

Weka is easy to learn.I am using it for a year to solve data mining problems. I can directly fit the data to any machine learning algorithm available in weka which makes my job simple without worrying about coding. One can experiment with their data set by applying various algorithms to know which model gives more accuracy quickly.