Hmm, I didn't know it was on MongoDB. Their site looks so pretty I was deceived into trusting them with my bitcoins (or fractions thereof).

Nope. I'm very concerned. That said, I don't use Coinbase (I use blockchain.info for storage.)

Coinbase's buy mechanic is very easy and allows you to not have a bunch of money stuck inside an exchange. You pay for the pleasure, of course, but if you aren't dealing in big money the fee's are negligible. Once you have your btc you can move it anywhere. I'm fully verified so I can insta-buy $1000 in BTC a day if I like which is more than enough for me ($1000/wk instant buy limit).

I've had issues with them before. They blamed it on getting out of sync with the blockchain, but it made no sense as your purchase cannot suddenly disappear due to that.