Thank you, Michael. That is good to know. In my experience, SemanticImport simplified a lot of things, like defining objects for different manipulations, or even just reading the file (I had a lot of issues with encoding from Windows to OSX and vice-versa). Although some simple calculations could be done with Import, the syntax was intuitively easier to understand by using SemanticImport for the most complex tests.
I'll keep an eye on this, anyway. The data set in this example is highly ideal (it does not have missing data, for example). I would expect SemanticImport to be able to handle this. It is good to know that in the case of trouble, some other options are available.