Biggest disadvantages are going to have to be the confirmation problem with bitcoin where nothing is instant and you must wait for someone to confirm the transaction[1]. I guess it is a trade-off being that it's impossible to recover but it's still kind of annoying.
Another annoying this has got to be the lack of adoption of bitcoin in the day to day world where you're forced to buy things with fiat cash instead of bitcoin[2].
[1] It might not be instant but it's much better than Western Union or other money remittance services. Back then, to send money overseas, you would have to be present in their store/shop so you can fill up a form, write your signature, hand the money, etc. But with bitcoin, we don't need to do all of these stuffs. Just imagine that 15 minutes of waiting as the same time that you'll spend when you drive to the store and do the necessary stuffs.
[2] The day before you're about to buy something in mall or something, withdraw your money from the local exchanger so it would be in your card the next day.
It's not that hard to keep some fiat with you or in your card since not all of your money is in bitcoin form.