It is a decent option, but the bottom line is that you DO NOT hold control of the private keys. This means that if something happens to Coinbase (as a company), or if the government or something comes through and tells them to freeze your account (for any reason), then you cannot access your coins.
By using Coinbase as your wallet, you are trusting them to hold onto all of your funds, and there is no guarantee that if something happens that you will get your coins back.
I use them to purchase BTC, and I keep a very small amount there, but I would not leave the majority of my holdings there.
Also, (and this is my opinion), because of how much they are into compliance and things like that, I could see them being the very first company to start issuing 1099s to their users around tax time...
Well, that is a very good reason not to use them then, I am going to have to think about other ways to do this. I guess my problem is selling the coins if I want to sell them, they are so easy to do but I definitely don't want to get taxed on that.
So if I have a flash drive I can create a cold storage correct? Then when I connect it to a computer, I just want to make sure it is not on the internet?
I am new on this so sorry about the questions!