As for me the biggest disadvantage looks like If your credit card is stolen or somebody hacks into your bank account there is a good chance you will not lose any money as banks will fix your balance. Even cash can be potentially recovered if the police acts fast. But with Bitcoin if you lose it you lost it for good. There is no mechanism to recover stolen or lost Bitcoins. If somebody hacks into your wallet where you store your Bitcoins you lost them for good. The best way to store your Bitcoins is on disk that is disconnected from the internet.