I was hiring for a telehealth startup based in NYC and got some referrals to some recent General Assembly grads. I bit and went ahead and scheduled some interviews. It was a total joke, honestly. The graduates glossed over the entry-level interview questions with a lot of handwaving (I would ask them things like "How would you do x given y?") and quoted rates upwards of $100/hr even though their total experience was the 10 week course @ GA campus.
I was so turned off by that experience that I just never even considered hiring from a 'hacker bootcamp' again. I'll echo what others have been saying as well: You can hire them, and maybe they'll perform for a while - but the amount of time you'll need to spend to get them up to speed on CS basics will more than likely not be worth the investment. You're better off hiring a recent college grad whose only experience is working with Java - at least they have the fundamentals and can build on top of them instead of backtracking.