This makes me have second thought about them. The good part would be the would surely manage to introduce BTCitcoin to some of it's users and the bad part would be, not sure if it would be entirely safe to use browser base wallets,
the in browser feature should only be used for pocket money amount to pay someone a few cents as a tip..
for larger amounts it would be advisable to send it to a non bitgo address. same principles of only using coinbase or blockchain.info for daily spend and then cold store for lifetime savings
on the faq tab they said "we will use BTC only for permissionless payment delivery to user and publisher wallets that we will create using BitGo’s APIs" meaning we can't use our own created wallets unless it's created with BitGo's API which is a big turn off for limiting users to use BitGo wallets only (for those who don't know, BitGo is restricted for some countries).
well its just a feature.. nothing will stop you copying and pasting the bitcoin address from the page itself into your own client rather then within the browser extension/widget