While the thesis based freeform option is liable to lead to practically learned mastery, it is perilous. What you might set out to learn and to do might not pan put. You might have to revise your ideas, redesign your studies. You may very well take a lot longer than 4 years through no fault of your own.

It can also feel incredibly demoralizing to be toiling in those trenches. Feeling like you are qualified for the job but you just need to get these damn experiments to finally work so you can actually leave and no longer be impoverished.