Pros
You can choose whatever shift you want that is available near you. There are preference settings on the website that shows you only the shift times and mile radius from your zip code. The flexibility in choosing your shifts is absolutely incredible. You don't have to interact with the company too much if you don't want to, but they are available for you to call 24/7. You can receive benefits if you pick up enough shifts to be considered full-time over a certain period (6 months I believe?)
Cons
While they're always available for you to call, that also means they send lots of texts to you about what shifts they think you might want to pick up. It can be helpful, but can also be somewhat annoying. If you pick up a shift, they want to make sure you are VERY committed to that shift. If you pick up a shift, then cancel, you have to pay what they call a "booking fee". I have been working there for four months and it still isn't clear to me how much the booking fee is. It's also difficult to get a clear-cut answer to what "stat, emergency, and crisis" pay mean respectively for how much extra money is made per hour by the employee. Something else they don't tell you upfront is that you can negotiate with your staffing agent about how much you want to be paid for certain shifts (especially if you have to drive farther for them).