>There is a core of very serious cases, like schizophrenia and some bipolar sufferers, but those are not mental illnesses, they are physical ailments with psychological symptoms. Purely mental illnesses have no scientific explanation, no reliable diagnostic criteria, and no treatments -- which is why the DSM is being abandoned.
What about depression? OCD? Anxieties? Are they "physical ailments with psychological symptoms"?
Some time ago I used it to quickly change my layout from qwerty to colemak, and often it couldn't keep up with my speed (and I'm an average typist: ca. 65 WPM), which resulted in wrong order of characters. I tried both interpreted and compiled version - no difference. It wasn't a beefy machine, though, so with your i5s and 8 gigs it may work well ;-).