Cons are obvious, he will never properly learn or master how to learn a Gemara on his own.
It is one thing people who do not have the time or capacity to learn on your own use it, but why should a Yeshva bachur who has the time and is capable use it.
Pros – even when you learn on your own, it is always handy when you get “stuck” to have it as a reference or just for difficult words as translator etc.
Have it for your additional Mesechete to study..
Bottom line, it depends for whom and when..