Coinbase, Poloniex, Kraken, CEX, you name it.. they're all crap. Eventually they will poop out on you. YES, especially when you are trying to buy the coin when it just crashed due to everybody panicking. Or even better yet, when you're trying to sell through a wallet and the site crashes and you lose a client (or at least you get them angry after they're forced to wait for a few hours). ALWAYS, always spread out your risk. Have coin on multiple wallets. Both online and offline. Never trust any one site or exchange. Only the paranoid survive in the crypto world. Hope for the best, expect the worst. Cheers.