Ask HN: Activate Robinhood?

I finally got an invite to the Robinhood app (free stock trades - Robinhood.com). I'm already using an online broker which charges me a fee ~$10.

Should I activate my Robinhood account? What have you'll heard or experienced with it? My fear is that it's a new company and their systems may not be as reliable as one would expect, although that may just be me.