They are one of the few reputable companies in the space. They follow all the laws, have a great looking site, have an exchange called GDAX under the same system if you want to try trading at some point, and they are pretty secure. Not to mention that any USD in your account is FDIC insured, and any Bitcoin is insured privately in case of a breach of their systems.
You will need to provide your id and it may take a week or more to get verified, and the fees are higher than alternatives, but honestly it's not that big of a deal, and it just reaffirms that they are trying to build a sustainable business and aren't going to close up shop tomorrow.